Preheat your oven to 170 degrees, fan bake and line 2 baking trays with baking paper.

In a bowl, cream together the butter and sugar.

Add in the egg and vanilla. Mix together until well combined.

Sieve in your, flour, cocoa and baking powder, before adding in your chopped white chocolate. Mix everything together, until the mixture is just combined.

Dampen your palms with a little bit of water and then take a heaped teaspoon of the dough to form into your cookie. Roll the dough between the palms for your hands to form a small ball. Then press to form the dough into round disks. Arrange the shaped cookies on your baking trays with a bit of space between each cookie.

Bake in your preheated oven for about 10 minutes. When they are ready your cookies will be firm on the edges and just cooked through in the middle.

Remove from the oven and allow to cool fully before placing your baked cookies into an airtight container to store.