Preheat oven to 350F and line a baking sheet with parchment paper, I also lightly spray it.
In a bowl using an electric mixer cream together your butter and sugar, add in peanut butter, egg and vanilla and beat for 2 minutes.
Stir in flour and baking powder till well mixed.
Using your hands roll dough into small balls, each one approximately 1 tsp of dough, these are mini cookies, if you don't get 36 or close to then you are making them too big.
Place rolled balls of dough on cookie sheet and press down with a fork.
Bake in the oven for 8-10 minutes, let cool 5 minutes.
Store in a sealed container, you can freeze these cookies if you wish.
Makes 36 mini cookies