Preheat the oven to 350 F.

In a medium bowl, combine the flour, baking powder, baking soda, and salt. Stir to blend thoroughly and set aside.

In a mixing bowl with an electric mixer, beat the butter with the peanut butter, brown sugar, and granulated sugar until light and fluffy.

Add the egg to the butter and sugar mixture and beat until blended.

Stir the dry mixture into the wet mixture until well blended.

Fold in the chocolate chips and chopped peanuts, if using.

Drop the dough but teaspoonfuls onto the prepared baking sheet.

Bake the cookies for 10 to 12 minutes, or until the bottoms are lightly browned.