Preheat oven to 350 degrees
In a large bowl sift together flour, cocoa and baking powder.
In a separate bowl combine butter and sugar.
Mix together on medium speed until well combined
Add eggs one at a time and mix well.
Then add the vanilla and mix well.
Add 1/3 of the flour mixture to the sugar mixture and mix well.
Continue with another 1/3 and then the final portion until the dough is well mixed.
Split the dough into 2 pieces.
Wrap each piece in plastic wrap and refrigerate for 1 hour.
Remove one of the sections of dough and roll out on a well floured surface.
Dip the cookie cutter into flour to prevent sticking and cut out shapes.
Fill two baking sheets and bake for 5 minutes.
Then switch the pans, moving the one on the top rack to the bottom, and the one on the bottom to the top.
Bake for an additional 5 minutes.
Remove from oven and let cool for a few minutes.
Transfer warm cookies to a cooling rack or tea towel.
Once cool, fill with buttercream icing and serve or place in a covered container.