Preheat oven to 350 F. Prepare baking pan with parchment paper.
In a large bowl mix butter and confectioner's sugar with electric mixer until it will become smooth.
Add egg and vanilla extract. Beat until all ingredients will combine.
In a separate bowl combine flour and baking powder. Add to wet ingredients.
Mix with mixer, then knead the dough by hand.
Flour the surface and roll the dough until 1/4 thick. Add flour when necessary. Cut the cookies with circle cookie cutter.
Lay nicely on parchment paper. Bake for 6 - 10 minutes. Start checking after 6 minutes so they will not burn out.
Cool off cookies completely before frosting.