# What You’ll Need:
→ Cake
01 - 2 cups all-purpose flour
02 - 1 1/2 teaspoons baking powder
03 - 1/2 teaspoon baking soda
04 - 1/2 teaspoon salt
05 - 1/2 cup unsalted butter, softened
06 - 1 cup granulated sugar
07 - 2 large eggs
08 - 1 teaspoon vanilla extract
09 - 1/2 cup cinnamon-flavored soda
10 - 1/2 cup sour cream
11 - 1/3 cup rainbow sprinkles
→ Cinnamon Streusel
12 - 1/3 cup all-purpose flour
13 - 1/4 cup brown sugar
14 - 2 teaspoons ground cinnamon
15 - 1/8 teaspoon salt
16 - 3 tablespoons unsalted butter, cold and cubed
# How-To:
01 - Preheat the oven to 350°F. Grease and flour an 8-inch square baking pan or line with parchment paper.
02 - In a small bowl, blend flour, brown sugar, cinnamon, and salt. Cut in cold butter using a fork or pastry blender until coarse and crumbly. Place streusel in refrigerator until ready to use.
03 - In a medium bowl, whisk together all-purpose flour, baking powder, baking soda, and salt for the cake base.
04 - In a large bowl, beat the softened unsalted butter and granulated sugar until pale and fluffy, approximately 2 minutes. Incorporate eggs one at a time, mixing thoroughly after each. Blend in vanilla extract.
05 - In a separate bowl or measuring cup, combine cinnamon-flavored soda and sour cream until homogeneous.
06 - Add the dry mixture to the butter mixture in three additions, alternating with the soda-sour cream blend. Start and finish with dry ingredients, mixing only until just combined.
07 - Gently stir rainbow sprinkles into the batter to evenly distribute.
08 - Transfer batter evenly into prepared pan. Sprinkle cinnamon streusel uniformly over the surface.
09 - Bake for 32 to 37 minutes, or until a toothpick inserted in the center emerges mostly clean.
10 - Allow cake to cool in pan for 15 minutes, then remove and cool completely before slicing.
