01 - Preheat oven to 350°F. Grease and line two 8-inch round cake pans with parchment paper.
02 - In a medium bowl, whisk together flour, baking powder, and salt until well combined.
03 - In a large bowl, beat butter and sugar on medium-high speed until light and fluffy, about 3-4 minutes.
04 - Add eggs one at a time, mixing well after each addition. Stir in vanilla extract.
05 - With mixer on low, add flour mixture in three additions, alternating with milk, beginning and ending with flour. Mix until just combined.
06 - Gently fold in chopped strawberries, then sprinkles, being careful not to over-mix to prevent color bleeding.
07 - Divide batter evenly between prepared pans. Smooth tops and bake for 28-32 minutes, or until toothpick inserted in center comes out clean.
08 - Let cakes cool in pans for 10 minutes, then turn out onto wire racks and cool completely.
09 - Beat butter on medium speed until creamy (about 2 minutes). Gradually add powdered sugar on low speed. Add strawberry puree, vanilla, salt, and beat until smooth and fluffy. Add milk 1 tablespoon at a time if needed.
10 - Place one cake layer on serving plate. Spread with strawberry buttercream. Top with second layer and frost top and sides with remaining buttercream. Decorate with extra sprinkles if desired.