In a large bowl, add the soft butter, granulated sugar, and brown sugar, and cream it with a hand mixer until it is light and fluffy.
Once the mixture is light, add egg and egg yolk to it, one at a time. Add the vanilla essence along with the eggs.
After the eggs are incorporated, sift in the flour, cocoa powder, baking powder, and salt. Fold them into the mixture with a spatula to combine everything.
Wrap the dough and refrigerate for one hour.
Once the dough has rested enough, take it out of the refrigerator and knead it a little bit. Kneading will help give a smoother surface to the cookies.
Roll the dough out between two pieces of baking paper to avoid the dough from sticking to your work surface.
Roll it to ¼ inch thickness and cut circles out with the cookie cutter. Transfer them to a baking tray lined with baking paper and again refrigerate for 20 minutes.
The second round of refrigeration will help the cookies cool and spread them evenly while baking.
Once the second round of refrigeration is done, preheat the oven at 325 degrees Fahrenheit for 10 minutes.
After that, place the baking tray in the oven and let the cookies bake for 10 minutes. Do not overbake them as that might turn them bitter.
Once baked, lay the cookies out on a wire rack and let them cool completely.
Roll the fondant out to ½ inch thickness on a surface dusted with icing sugar. Cut out circles with the same 2-inch cookie cutter and keep them aside.
Serve immediately or store for later!