Preheat oven to 350 degrees F.
In the bowl of an electric mixer, blend butter and peanut butter until smooth and creamy. In a separate bowl, whisk together flours, baking powder, baking soda, and salt.
Add brown sugar to peanut butter mixture and blend until smooth. Add egg and vanilla, and beat until incorporated. Reduce speed to low. Add dry ingredients, and mix until combined.
Scoop level tablespoons of dough, and form into balls. Roll into tablespoon-sized balls, then roll in the sugar to coat.
Transfer cookie balls to parchment-lined baking sheets, spacing about 2 inches apart. Bake until cookies are puffy, about 10 minutes.
Remove from oven, and make indentations in centers by pressing with the handle end of a wooden spoon. Return to oven, and bake until edges are golden, 6 to 7 minutes more.
While cookies are still warm, fill each cookie with 1/2 teaspoon of fruit preserves.
Transfer sheets to wire racks, and let cool completely.