This Holiday Celebration cake takes a boxed chocolate cake mix and turns it into a showstopper with a homemade butter custard filling, chocolate ganache, and Italian meringue buttercream.
In this post you will learn:
- How to make a delicious and moist cake using boxed cake mix.
- The steps to make a butter custard filling that is silky and decadent (Spoiler Alert…you are going to need A A LOT of egg yolks).
- How to make a perfect and simple chocolate ganache.
- The steps to make Italian Meringue Buttercream with step by step photos.
Yes, there are 4 layers to this cake and they are all fantastic.
Just to clarify, most of the failures involved the appearance of the cake, not the taste.
However, an ugly cake is, well…an ugly cake.
The Naked Style Holiday Celebration Cake
Then came the “naked cake” and my cake-making life changed. A naked cake is basically a cake that doesn’t have any icing (or very little icing) on the sides. It relies on the filling and topping for the WOW factor.
To be called a Holiday Celebration Cake, the filling and topping had better be spectacular, which this Vanilla Butter Custard and Italian buttercream certainly is.
The butter custard alone is the thing dreams are made of. With 10 egg yolks (yes, I said 10) and 2.5 sticks of butter, it had better be!
And that is just the filling.
Then imagine a chocolate ganache top with little clouds of light Italian buttercream.
Are you starting to see why this is a celebration cake? It is truly special.
The cake in this recipe may seem familiar to those of you that have seen the post for Chocolate Cherry Chunk Cake. That’s because it is my go-to recipe for most of the cakes I make. I have tested MANY other recipes, but have never found one that is as easy, moist, tasty, or as reliable as this one. It is also very versatile so you can customize it to your needs by swapping out the cake mix and pudding mix for your flavor of choice.
Tips for success: chill each component prior to assembling the holiday celebration cake
I made this cake last year for our annual New Year’s Eve party and it was a hit because the taste was incredible. However, I have since had to make some modifications because the cake wilted in the warm kitchen and wound up looking like the leaning tower of Pisa…with melty whipped cream frosting sliding off the top.
Live and learn… and adjust.
Lesson learned, recipe adjusted.
The next time I made it, I made sure that all of the ingredients were chilled prior to assembling, switched out the whipped cream topping for an Italian Meringue Buttercream, then popped the cake in the refrigerator until 2 hours before serving.
It was perfect.
For those of you that have never made an Italian buttercream, you are in for a treat! It is SO much fun and even though it might seem intimidating, it’s really quite easy.
Even though it is considered one of the fussier icings to make, I have never had any issues.
Why is it fussy? Well, you need to make sure you follow the directions closely. The consistency of the egg whites are important as well as getting the temperatures right.
No need to worry, though. I’ll take you through each step.
Chocolate cake with Vanilla Butter custard and Italian buttercream:
How to make the easy and moist chocolate cake:
Add all ingredients for the cake batter in a medium bowl.
Mix until the batter is smooth and fluffy.
Divide the batter between two greased 9-inch round pans.
Bake at 350 for 20-25 minutes (mine took 22 minutes). Let the cakes cool for 20 minutes and then remove them from the pan by inverting them onto a cutting board or flat platter. Cool completely.
How to make the butter custard filling:
Combine the egg yolks and sugar in a medium heavy sauce pan.
Slowly add the hot milk (I just popped mine in the microwave until hot, but not scalding) to the egg yolk mixture, stirring constantly until mixed well.
Heat over medium-low to medium heat, stirring constantly with a heat proof spoon. Continue stirring until the egg mixture thickens (about 20 minutes, but time varies depending on the heat).
I wouldn’t recommend rushing this step. The slower you heat the mixture, the smoother the custard will be. Don’t worry too much if you do have lumps in the mixture because we will pass it through a sieve to ensure a smooth consistency. (This post contains affiliate links.)
You know it is done when it has thickened and coats the back of a spoon. You should be able to run your finger through it without any running.
Add the vanilla and butter (4 tablespoon at a time).
Stir until the butter is melted and is well incorporated.
Then pass the custard through a fine mesh sieve to remove any lumps. You will need to use a spoon to push the thick custard through.
Cover the bowl with plastic wrap (touching the custard to prevent a skin from forming) and put into the refrigerator to cool.
After the cake is completely cooled, level the top and cut each cake in half with a large serrated knife so that you have now have 4 flat layers. Don’t be worried if it’s not perfect. Rustic cuts will some character to the cake. My cakes always have a bit of character!
Spread the custard between each cake layer (you will use a little over ½ cup of custard per layer). The custard may spread with the weight of the cake layers so leave a little room around the edges.
How to make a chocolate ganache:
Place the chocolate chips, cream, and butter in a small microwaveable bowl. Microwave on high until mixture is warm and the chocolate begins to melt. Stir until chocolate is completely melted and the ganache is smooth. Spread the ganache onto the top of the cake within ½ inch of the edge.
If the assembled cake seems a little loose or the custard begins to run, then place the cake into the refrigerator to chill.
How to make an Italian Meringue Buttercream
Beat the egg whites
Add 2 egg whites, salt, and cream of tartar to a stand mixer bowl with a whisk attachment. Turn the mixer on low to mix everything for about 20 seconds and then increase the speed to high. After 1 minute, slowly add in 2 tablespoon + 2 teaspoon sugar.
Continue to beat on high speed until soft peak stage (the meringue will be slightly firm but the peak will flop when the whisk is inverted). Turn the mixer off and set aside.
Make the simple syrup
Add ½ cup sugar and water to a small sauce pan and mix well to dissolve the sugar.
Add a candy thermometer to the side. Bring to a boil over medium heat, swirling the liquid in the pan occasionally to prevent burning. Boil until the liquid reaches 240 degrees. This can happen quickly so don’t walk away!
Add the simple syrup to the egg white mixture
Turn the mixer on low and gently add the sugar syrup in a very thin, slow stream to the egg whites. Be VERY careful as the sugar is VERY hot.
Add the butter
Turn up the mixer speed to medium and add 1 tablespoon of SOFTENED butter at a time until all of the butter is added. Do not be concerned when your meringue deflates some at this point. It will gain its structure back after all the butter is added. The temperature of the butter is very important. It must be very soft but not melting. Too melty and you’ll have soup. Too firm and you will have lumps of butter in the meringue. If you realize the butter is too soft, just continue on but you will need to throw it into the refrigerator to chill slightly before whipping it back up.
Whip until light and fluffy
Turn the speed up to medium-high and whip until the buttercream is silky and fluffy. If it remains on the soupy side, then throw it in the refrigerator to chill for a few minutes, then whip once again.
Pipe the Italian Meringue Buttercream onto the Holiday Celebration Cake
Add buttercream to a piping bag fitted with a #21 star tip. Using a tall glass makes this job easier.
Twist the top of the bag to prevent the buttercream from coming out the top.
Pipe the Italian Buttercream onto the top of the cake using a #21 star tip and piping bag. If you haven’t attempted this before I recommend practicing on a piece of wax paper prior to piping onto your cake.
Holiday Celebration Cake
- 1 box chocolate, fudge or devils food cake mix
- 1 box (3.6-3.8) chocolate (dark or milk) pudding mix
- ½ cup sugar
- 4 large eggs
- ¾ cup vegetable oil
- ½ cup water
- 8 oz sour cream
- ½ tablespoon pure vanilla extract
Vanilla Butter Custard:
- 10 large egg yolks reserved 2 of the egg white for the Italian buttercream
- ⅔ cup sugar
- ⅔ cup very warm milk
- 1 teaspoon 1 vanilla
- 20 tbsp (2.5 sticks) salted butter
- ½ cup dark chocolate chocolate chips
- 2 tablespoon heavy whipping cream
- ½ tablespoon salted butter
- 2 large egg whites
- ⅛ teaspoon cream of tarter
- ⅛ teaspoon salt
- 2 tbsp + 2 tsp sugar
- 2 tbsp + 2 tsp water
- ½ cup sugar
- 1 teaspoon pure vanilla extract
- 2 sticks salted butter very soft and cut into tablespoons
Make the cake:
- Preheat oven to 350 degrees.
- In a large bowl combine the cake mix, pudding mix, sugar, eggs, vegetable oil, water, sour cream, and vanilla.
- Beat on medium speed with hand held mixer for 2-3 minutes, until light and fluffy.
- Divide the batter between 2 greased 9-inch round nonstick pans.
- Bake at 350 degrees for 20-25 minutes (mine took 22 minutes) or until a toothpick comes out clean when inserted into middle of the cake.
- Allow the cakes to cool in the pans for 20-30 minutes then carefully remove the cakes from the pan by inverting onto a plate.
- Allow the cakes to cool completely.
Make the Vanilla Butter Custard:
- While the cake is baking, Combine the egg yolks and sugar in a medium heavy sauce pan. Stir well.
- Slowly add the warm milk, stirring constantly until combined. Heat over medium-low to medium heat, stirring constantly with a heat proof spoon.
- Cook until the egg mixture thickens and coats the back of the spoon, about 20 minutes. Careful not to heat the mixture too quick as it can curdle.
- Once the mixture is thick and coats the back of a spoon, turn off the heat and add vanilla and butter (4 tablespoon at a time), stirring until well incorporated.
- Pass the custard through a fine mesh sieve into a medium bowl.
- Cover with plastic wrap (touching the top of the custard to prevent a skin from forming) and place in the refrigerator to chill.
Make the ganache:
- After the cakes have cooled, make the ganache.
- Place the chocolate chips, cream, and butter in a small microwaveable bowl.
- Microwave on high until mixture is warm and the chocolate begins to melt.
- Stir until chocolate is completely melted and the ganache is smooth.
Make the Italian Meringue Buttercream:
- Add 2 egg whites, salt, and cream of tartar to a stand mixer with whisk attachment.
- Turn the mixer on low for about 20 seconds to combine the ingredients and then increase the speed to high.
- After 1 minute, slowly add in 2 tablespoon + 2 teaspoon sugar.
- Continue to beat on high speed until soft peak stage (the meringue with be slightly firm but the peak will flop when the whisk is inverted).
- Turn the mixer off and set aside. Add ½ cup sugar and 2 tablespoon +2 teaspoon water to a small sauce pan and mix well to dissolve the sugar.
- Add a candy thermometer to the side.
- Bring to a boil over medium heat, swirling the liquid in the pan occasionally to prevent burning.
- Boil until the liquid reaches 240 degrees.
- This can happen quickly so don’t walk away!
- Turn the mixer on low and gently add the sugar syrup SLOWLY in a stream to the egg whites.
- Be VERY careful as the sugar is VERY hot.
- Turn the mixer to medium speed and continue whipping until the meringue is cool to the touch (if it’s too warm, your butter will melt in the next step).
- With the mixer on medium speed, add 1 tablespoon butter at a time until all of the butter is added.
- Make sure each tablespoon of butter is incorporated before adding the next.
- Do not be concerned when your meringue deflates some at this point.
- It will gain its structure back after all the butter is added.
- Turn the speed up to medium-high and whip until the buttercream is silky and fluffy.
- If it remains on the soupy side, then place it in the refrigerator to chill for a few minutes, then whip once again.
Assemble the Cake:
- Level the top of each cake and then cut each in half, horizontally.
- Fill each layer with ½ cup (a little over) of the Vanilla Butter custard.
- Top with chocolate ganache.
- Pipe the Italian Buttercream onto the top of the cake using a #21 star tip and piping bag.
- Refrigerate unused buttercream.
- Eat the cake immediately or keep chilled in the refrigerator.
- Remove from the refrigerator 2 hours before serving.