Crush the biscuits in a mortar. Then heat the butter in a saucepan and mix it with the crushed biscuits.
Lay out paper liners in a muffin tin and distribute the cookie dough evenly in the molds and press down to create a cookie base.
Mix the remaining ingredients except for the lemon. Wash off the lemon and rub it with a nutmeg grater. Now add the lemon zest to the other ingredients and pour the mixture into the muffin cups.
Preheat the oven to 180 degrees and bake the cupcakes for about 20 minutes.
Then let cool for 1 hour and place in the refrigerator for at least another 3 hours. This is how the cupcakes get the right consistency.