Preheat Oven: Preheat your oven to 350°F (175°C). Grease and line a jelly roll pan with parchment paper.

Make the Batter: In a medium bowl, combine the flour, sugar, cocoa powder, baking powder, and salt. In a separate bowl, whisk together the eggs, water, oil, and vanilla extract. Gradually add the wet mixture to the dry ingredients, mixing until smooth.

Bake the Cake: Spread the batter evenly in the prepared jelly roll pan. Bake for 15 minutes, or until the cake springs back when lightly pressed.

Roll the Cake: Once baked, carefully turn the cake onto a clean kitchen towel dusted with powdered sugar. Roll the cake gently (starting from a short side) with the towel inside. Let it cool completely while rolled.

Prepare the Filling: In a bowl, beat the peanut butter and powdered sugar until smooth. Fold in the whipped cream to create a fluffy filling.

Assemble the Roll Cake: Gently unroll the cooled cake and spread the filling evenly over the surface. Sprinkle mini chocolate chips on top of the filling. Roll the cake back up tightly without the towel.

Refrigerate: Wrap the roll cake in plastic wrap and refrigerate for at least 1 hour to set.

Serve: Slice the cake and drizzle with chocolate sauce for extra indulgence, if desired.