Melt the chocolate. Set a medium heatproof bowl over a small pot of simmering water. Make sure the bowl is completely dry. Add the chocolate and melt over the heat, stirring frequently. Set aside to cool.

Mix dry ingredients. In a medium bowl, combine the flour, cocoa powder, baking powder, and salt. Set aside.

Cream butter and sugar. In the bowl of a stand mixer fitted with a paddle attachment, beat the butter and brown sugar until light and fluffy, about 2 minutes.

Add chocolate, eggs, and vanilla. Add the cooled chocolate to the creamed butter and sugar, and mix well. Add the eggs and vanilla and mix well.

Add dry ingredients and milk. Add half of the dry ingredients, then half of the milk, and mix to combine. Add the remaining dry ingredients and the rest of the milk. Mix well, scraping down the sides and bottom of the mixing bowl with a spatula.

Chill the dough. Place the mixer bowl in the fridge and chill the dough for at least 1 hour 30 minutes and up to 2 hours 30 minutes. If you need to cut down the chill time, you can instead place the bowl in the freezer for 45 minutes.

Prep your tools. Preheat the oven to 350F and line two baking sheets with silpats or parchment paper.

Prep the rolling sugar. Get two small plates. In one place the granulated sugar. In the other, place the confectioner’s sugar.

Roll the dough. Scoop about 1 1/2 tablespoons of cookie dough and roll it into a ball. The dough will be sticky. Roll the cookie dough ball in the granulated sugar, then roll it in your hands a bit more to get a nice spherical shape. Lastly, place the cookie dough ball in the confectioner’s sugar and gently move it about to cover all sides with a thick coat of sugar. Place each ball on your prepared cookie sheet, making sure there are at least 2 inches of space between each ball of dough.

Bake. Bake the cookies for 15-16 minutes until cracks form. You may need to bake in two batches, depending on how many ovens you have and/or the size of your ovens.

Cool. Let the baked cookies cool for at least 30 minutes before attempting to remove them to a cooling rack. This is very important. If you try to move them too soon the bottoms of the cookies will break.