Preheat oven to 350F (175C) and lightly grease and flour the bottom and side of a 13”x9” baking dish. Set aside.

For the topping

In a large mixing bowl (or the bowl of a stand mixer fitted with the paddle attachment) use an electric mixer to cream butter and sugars together until well creamed.

Add vanilla extract and mix until combined.

In a separate medium sized bowl whisk together flour, baking powder, and salt.

Gradually add flour mixture to butter mixture, stirring until just combined. Mixture will be dry and sandy.

Add sprinkles and use your hands to evenly incorporate them into the mixture, pinching dough together to make clusters. Mixture should resemble streusel with varying size of clumps. Set aside while you prepare your cake.

For the cake

In a large mixing bowl (or the bowl of stand mixer fitted with the paddle attachment), use an electric mixer to beat together cream cheese, butter and sugar until light, creamy, and free of lumps.

Add eggs and vanilla and stir well. Scrape down the sides and bottom of the bowl to be sure to incorporate all ingredients into batter.

In a separate, medium-sized bowl whisk together flour, baking powder, and salt.

Gradually add flour mixture to the batter, alternating with the buttermilk, until all flour and buttermilk have been combined. I typically add the flour in 4 parts and the buttermilk in 3, starting and ending with the dry ingredients.

Spread just under half of the batter evenly into the prepared pan. Take half of the crumble topping and spread evenly over top of the batter. Dollop the rest of the batter over top of the crumbles and gently spread evenly over top. Sprinkle the remaining crumbles overtop, pressing gently into the surface of the batter.

Bake in center rack of 350F (175C) oven for 45-50 minutes, until a toothpick inserted in the center comes out clean or with moist crumbs. Allow to cool before adding glaze (if using) and cutting and serving.

To make the glaze: In a medium sized bowl, whisk together powdered sugar, 2 Tablespoons of milk, and vanilla extract. Add additional milk as needed until glaze is smooth and reaches desired consistency. Drizzle over completely cooled cake and enjoy!