These blueberry streusel muffins are a Christmas morning tradition in our family. A thick and moist blueberry muffin batter is topped with a cinnamon sugar streusel topping that is just perfect for Christmas morning and will fill your kitchen with the most incredible cinnamon smell.
For the batter, mix the first 8 ingredients ( flour, sugar, salt, baking powder, vegetable oil, eggs, buttermilk, and vanilla) together in a medium bowl. The batter will be thick.
Stir in the blueberries.
Fill the muffin tins to the top with batter.
Make the steusel topping
Mix together the flour, sugar, and cinnamon in a small bowl.
Add the cubed butter and cut it in with a fork or pastry blender until the butter is incorporated and you have course pea sized pieces.
Sprinkle the streusel on top of the muffin batter.
Bake
Bake at 350 degrees for 20-25 minutes (may take a few minutes extra if the blueberries are frozen when you put it in the oven) until the center is just set and a toothpick comes out clean when inserted.