1. For the dough add the butter and sugar to a large bowl and mix until light and fluffy for several minutes. Add the egg and vanilla extract and mix until well combined. Mix the flour with the black cocoa powder, baking powder, and salt and add to the bowl – mix until just combined. Shape the dough into a ball, flatten it and wrap in plastic wrap. Place in the fridge for at least 2 hours or overnight.

2. Preheat the oven to 325°F (165°C). Line a baking sheet with baking parchment and set aside. Take about half of the dough and roll out thinly on a floured surface. Use Halloween cookie cutters and cut out as many cookies as possible, collect the scraps and roll out and cut out more cookies. Keep the rest of the dough in the fridge. Bake the first batch of cookies for about 10-11 minutes, then take out of the oven and let cool down a bit on the baking sheet. Transfer to a wire rack and let cool down completely. Repeat with remaining dough.

3. For the royal icing mix about 5.6 oz. (150g) of the confectioners’ sugar with the egg white and lemon juice, then add more confectioners’ sugar if necessary until you get a nice thick consistency – you don’t want the icing to be too runny. Fill into a piping bag with a small round tip and decorate the cookies to your liking. Let the finished cookies dry for at least 8 hours or overnight. Store in an airtight container in a cool place.