Preheat your oven to 350°F and grease two 9-inch round cake pans—one for the red layer, one for the blue. In a medium bowl, whisk together flour, baking powder, and salt. In another bowl, cream butter and sugar together until it looks fluffy and pale, about 3 minutes. This step matters because it adds air to your cake.

Beat in eggs one at a time, making sure each one's fully combined before adding the next. Add vanilla extract and mix it in. Alternate adding flour mixture and milk to the butter mixture, starting and ending with flour. Mix on low speed so you don't overbeat it—this keeps your cake tender.

Divide batter into two bowls. Stir strawberry jam into one portion for your red layer, then pour into the first prepared pan. Stir blueberry compote into the second portion for your blue layer and pour into the second pan. Bake for 35 minutes until a toothpick inserted in the center comes out clean and the tops look golden.

Let both cakes cool in their pans for 10 minutes, then turn them out onto wire racks completely. This step takes patience but trust me—rushing this makes your frosting melt into the warm cake. Once completely cool, use a serrated knife to carefully slice each cake horizontally into two thin layers (you'll have four layers total).

Make the white chocolate frosting by folding white chocolate chips into whipped cream gently until they soften and blend throughout. Don't overmix or you'll deflate all that fluffy whipped cream. Taste it and adjust—add a tiny pinch of salt if it feels too sweet.

Place your first red cake layer on a serving plate and spread frosting over it. Sprinkle your patriotic candies (think red, white, and blue M&Ms or star-shaped candies) generously across that frosting layer. Stack the next layer and repeat with frosting and candies—this creates your hidden surprise inside the patriotic pinata cake.

Continue with your blue layers, frosting, and candies between each one. Frost the outside of your whole cake with remaining whipped cream frosting, then decorate the top and sides with more candies in patriotic colors. Chill for at least 30 minutes before cutting so the layers hold their shape and those candy surprises stay tucked inside.