Preheat the oven to 350 degrees F (175 degrees C).
In a large bowl, mix together the peanut butter, butter, honey, brown sugar and egg until smooth. Combine the whole wheat flour and baking powder; stir into the batter until blended. Roll into small balls, and place on a greased cookie sheet. Flatten slightly using a fork.
Bake for 13 to 15 minutes in the preheated oven, or until cookies are slightly toasted at the edges.