1 1/2 cups flour
1/2 cup cocoa
1/2 teaspoon baking soda
1/2 cup softened butter
1/2 cup sugar
1/2 cup brown sugar
1/4 cup peanut butter
1 egg
1 tablespoon milk
1 teaspoon vanilla extract
3/4 cup sifted powdered sugar
1/2 cup peanut butter
2 tablespoons sugar

Heat oven to 350°F. Combine dry ingredients. Beat together butter, sugars and peanut butter till combined. Add egg, milk and vanilla. Beat in as much of dry mixture as possible. Stir in remaining dry mixture. Form dough into 1 1/4 inch diameter balls. Combine powdered sugar and peanut butter till smooth. Shape mixture into 3/4 inch balls. Slightly flatten dough ball and top with peanut butter ball. Shape dough around peanut ball, covering completely. Roll into ball. Place 2 inches apart onto ungreased baking sheets. Lightly flatten with bottom of glass dipped in sugar. Bake 8 minutes till just set and surface slightly cracks. Let stand 1 minute on baking sheets before removing to racks to cool.