Preheat the Oven: Preheat your oven to 350°F (175°C). Line a 10×15 inch baking pan with parchment paper.

Prepare the Cake Batter: In a large bowl, beat the eggs with an electric mixer until thick and light yellow, about 3-5 minutes. Gradually add the granulated sugar and continue beating until the mixture is fluffy. Sift together the flour, cocoa powder, baking powder, and salt. Gently fold the dry ingredients into the egg mixture until just combined.

Bake the Cake: Pour the batter into the prepared pan and spread evenly. Bake for about 12-15 minutes, or until the cake springs back when lightly touched.

Roll the Cake: While the cake is still warm, turn it out onto a clean kitchen towel dusted with powdered sugar. Remove the parchment paper. Starting from a short side, roll up the cake with the towel inside and let it cool completely.

Prepare the Filling: Whip the heavy cream, powdered sugar, and vanilla extract until stiff peaks form.

Assemble the Cake: Unroll the cooled cake and spread the whipped cream filling evenly. Add the sliced strawberries on top of the whipped cream. Roll up the cake again (without the towel) and place on a serving plate, seam side down.

Decorate: Drizzle the melted chocolate or ganache over the top. Pipe whipped cream on top and arrange additional strawberries for decoration.