Preheat oven to 375 degrees. In a bowl, combine flour and baking powder. In another bowl, mix peanut butter and milk. Add wet mixture to dry, and mix well.
Turn out dough on a lightly floured surface and knead. Roll out to 1/4-inch thickness and cut out shapes. Place on a greased baking sheet and bake 20 minutes or until lightly brown. Cool on a rack and store in an airtight container.