Chocolate Devil's Food Cupcake with Berries

Preheat oven to 350º F. Line muffin tins with paper or foil liners.

In a small bowl, whisk together cocoa and hot water until well mixed and smooth. In a separate bowl, whisk together flour, baking powder, baking soda, and salt. Set aside.

In a saucepan over medium-low heat, melt butter with sugar, stirring constantly to combine. Remove from heat; pour into a large mixing bowl. Using an electric mixer on medium-low speed, beat for 4 or 5 minutes. Add egg, one at a time, beating until incorporated. Add vanilla and cocoa mixture, and beat until blended. Reduce mixer speed to low. Gradually add flour mixture in two batches, alternating with sour cream. Beat until just combined.

Divide batter between lined muffin tins, filling them three-quarters full. Bake until cake tester inserted in centers comes out clean, about 20 minutes. Rotate tins halfway through the baking process, to promote even baking. Remove from oven; cool in pan on wire rack for 15 minutes. Remove cupcakes from pan and let cool completely.

For Whipped Cream Frosting:

In a large glass or stainless steel bowl, beat heavy cream until soft peaks form. Add confectioners' sugar and vanilla, beat until incorporated.

To Serve: