Cream the butter until it reaches a mayonnaise-like consistency. Gradually add sugar in 2–3 batches and mix well.

Add the egg in portions and mix thoroughly to prevent separation. The lecithin in the egg yolk acts as an emulsifier.

Divide the dough into two portions and place them in separate bowls. Add the respective dry ingredients to each bowl and mix well.

Sift the cocoa powder and add it to the chocolate dough mixture.

Fill each dough into separate piping bags. Place both bags into a larger piping bag fitted with a star nozzle.

Pipe the dough into desired shapes, such as circles or roses, onto a baking tray.

Bake in a preheated oven at 180°C for 15–18 minutes. Adjust time and temperature based on your oven's specifications.