# What You'll Need:
→ Cake
01 - 1 1/2 cups all-purpose flour
02 - 1/2 cup granulated sugar
03 - 1/4 cup unsalted butter, softened
04 - 1 large egg
05 - 1/2 cup whole milk
06 - 2 teaspoons baking powder
07 - 1/2 teaspoon salt
08 - 1 teaspoon vanilla extract
09 - 2 cups fresh blueberries (or frozen, unthawed)
→ Streusel Topping
10 - 1/2 cup all-purpose flour
11 - 1/2 cup packed light brown sugar
12 - 1/2 teaspoon ground cinnamon
13 - 1/4 cup unsalted butter, cold and cubed
14 - Pinch of salt
# How-To Steps:
01 - Preheat oven to 350°F and grease a 9-inch square baking pan, lining it with parchment paper.
02 - Whisk together flour, baking powder, and salt in a medium bowl; set aside.
03 - In a large bowl, beat the softened butter with granulated sugar until light and fluffy, then add the egg and vanilla, mixing thoroughly.
04 - Alternately add the flour mixture and milk to the butter mixture, beginning and ending with the flour, mixing just until combined.
05 - Gently fold in the blueberries, taking care not to crush them.
06 - Pour batter into prepared pan and smooth the surface evenly.
07 - Combine flour, brown sugar, cinnamon, and salt; cut in cold cubed butter with a pastry blender or fork until coarse crumbs form.
08 - Sprinkle streusel mixture evenly over the batter in the pan.
09 - Bake for 40 to 45 minutes until a toothpick inserted in the center comes out clean and the topping is golden brown.
10 - Allow to cool in the pan for at least 20 minutes before slicing and serving.