In a mixing bowl combine flour, cocoa powder, salt and baking powder. Set aside.
In a separate bowl beat unsalted butter and granulated sugar untill light and smooth.
Add eggs and vanilla extract. Beat again untill all combined.
Sift in dry ingredients and stir to combine.
Cover the dough with plastic wrap and refrigerate for a few hours or overnight.
Preheat the oven to 350 degrees Fahrenheit. Scoop dough with cookie scoop or ice cream spoon for even portioning into 18-20 cookies. After that roll cookie dough into even-sized balls.
Roll each ball into sifted powdered sugar.
Place cookies on the baking sheet, make sure to leave space between each of the cookies.
Bake cookies for 12-14 minutes.
Allow cookies to cool and then move them to a wire rack to fully cool down.