1. Dot the Inside
Measure 1/4 cup cocoa powder (for chocolate cakes) or flour (for all other types). Coat the fruit pieces lightly on all sides. Doing so helps them grab the batter and prevents the fruit color from bleeding into the mix. When adding the dusted fruit to the mix, be gentle. Fold the fruit into the cake batter until it’s evenly distributed, but be careful not to overmix.
2. Play with Color
To turn white cake a pleasing shade of pink, crush fresh raspberries with a fork, strain them and stir into the cake mix after you’ve mixed in all other ingredients. The more berries you incorporate, the more intense the flavor; fewer will yield a pastel hue. For a marbled effect, divide batter into two bowls. Stir crushed berries into one. Using two spoons, ladle the white and pink batters into the cake pan side by side, then swirl a toothpick through them.
3. Layer in Fruit
Strawberries, blackberries and other summer produce will maintain the freshest texture if they’re incorporated after baking. But that doesn’t have to mean only decorating the top. Try baking and cooling the mix cake, then slicing it horizontally. Place the fruit between the layers, and finish with a generous coating of buttercream icing.