Prepare the Sponge Cake: In a mixing bowl, beat together the eggs, sugar, and honey until smooth. Add salt and vanilla essence to the mixture for enhanced flavor.
Combine Dry Ingredients: Sift the flour and cocoa powder into the mixture and blend on low speed until well combined.
Bake: Pour the batter onto a greased 50x30 cm baking sheet and spread it evenly. Bake at 190-200°C for 8 to 10 minutes or until set.
Roll the Cake: Once done, sprinkle powdered sugar on top and gently turn the cake onto a sheet of parchment paper. Carefully peel away the original parchment, then roll the cake tightly while it’s still warm.
Make the Filling: In a saucepan, whisk together the milk, sugar, and cornstarch over medium heat. Stir until thickened. Once cooled, mix the butter until smooth and combine with the custard and cocoa.
Assemble: Unroll the sponge, spread the filling evenly, and roll it back up. Decorate as desired with nuts or chocolate shavings.