Preheat your oven to 350°F (175°C) and grease a jelly roll pan.
Whisk eggs and sugar in a bowl until light and fluffy.
Sift together flour, cocoa powder, and baking powder.
Fold dry ingredients into the egg mixture gently.
Spread batter evenly in the prepared pan.
Bake for 12-15 minutes until it springs back when touched.
Roll the cake in parchment paper to cool completely.
Whip heavy cream until soft peaks form and spread on the cake.
Roll the cake back up and cover with chocolate ganache.
Decorate with fresh berries and mint leaves before serving.