In a medium bowl, mix together (by hand) butter, sugar, cocoa powder, and baking powder. Once combined, add in vanilla and eggs and stir until incorporated. Lastly, add in flour and mix until combined.
Pour batter into greased 9x13 pan. Bake at 350 degrees for 20-30 minutes or until toothpick comes out clean. Cool completely.
Once brownies are cooled, layer strawberries, whipped cream, blueberries, and brownies into dessert dishes to create trifle. If you would like a more fruity dessert, use less brownies, and vice versa. Have fun with layering!