In a large bowl, whisk together flour, cocoa powder, salt, and baking powder.

In a mixing bowl, cream together butter and sugar until fluffy. Add eggs, one at a time, and then vanilla.

Slowly add flour mixture and beat just until combined.

Remove dough from bowl to waxed paper or plastic wrap. Shape into a square, wrap tightly in plastic wrap, and refrigerate for at least 2 hours to overnight.

Preheat oven to 350 degrees. Line baking sheet with parchment paper.

Roll out dough to ¼ inch thickness and cut using cookie cutter. Place on baking sheet.

Bake for 9 to 11 minutes until edges are set. Allow to cool on baking sheet for 10 minutes before transferring to cooling rack.

Cool completely before decorating as desired.