This blueberry coffee cake recipe is packed full of plump, juicy blueberries and topped with a buttery, brown sugar streusel. It rivals any bakery coffee cake!
Using the largest slots of a cheese grater, shred the frozen/ultra-cold butter into a bowl with flour.
Add brown sugar to the mixture. Stir to combine and set aside for later.
Cake
Preheat the oven to 350°F. In a large bowl, add the butter and sugar, beating until well combined and fluffy.
Add the vanilla extract and egg. Beat until smooth.
In a separate small bowl, combine the flour with baking powder.
Add the flour/baking powder mixture in small parts into the sugar/butter mixture. Alternate with a small splash of milk. Repeat this process until you run out of milk and flour.
Fold in the blueberries. Grease a 6-inch baking pan with butter. Spread the cake mixture evenly throughout the pan.
Spread the streusel topping over the top of the cake batter. Bake the cake for 50-60 minutes. When the cake is fully baked, a toothpick should come out of the center clean.