Step 1

Combine dry ingredients: Combine cocoa powder, flour, baking powder and salt in a medium bowl. Set aside.

Step 2

Cream wet ingredients: Place butter, sugar and vanilla in a large mixing bowl and beat with an electric mixer until combined. Add the eggs, one at a time, and mix on medium-low speed just until combined - about 10 seconds each.

Step 3

Make cookie dough: Add the dry ingredients to the egg mixture and mix on low speed until incorporated.

Step 4

Chill cookie dough: Cover the bowl and chill the dough for at least 1 hour or up to overnight (the longer you chill, the thicker the cookies will be).

Step 5

Roll cookies: When ready to bake, preheat the oven to 350°F. Place the powdered sugar in a medium bowl. Roll the dough into tablespoon-sized balls and cover them well with the sugar.

Step 6

Bake cookies: Place on a lined baking sheet with enough space between them (bake in batches) and bake for 10-15 minutes, or until spread and crackled. Cookies will still be soft, so let them cool on the baking sheet for 5 minutes before removing them to a cooling rack to cool completely.