Peanut Butter Munchies, aka "Cookie Crack"

I made this recipe for the first time on December 15th. 10 days later, I've made it four more times. It's amazing.
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1 1/2 cups all-purpose flour
1/2 cup unsweetened cocoa powder
1/2 teaspoon baking soda
1/2 cup butter, softened
1/2 cup granulated sugar
1/2 cup packed brown sugar
1/4 cup peanut butter
1 egg
1 tablespoon milk
1 teaspoon vanilla
3/4 cup sifted powdered sugar
1/2 cup peanut butter
2 tablespoons granulated sugar

Preheat oven to 350 degrees. In medium bowl stir together flour, cocoa powder and baking soda; set aside.

In a large bowl beat together butter, 1/2 cup granulated sugar, brown sugar, and the 1/4 cup peanut butter until combined. Add egg, milk, vanilla; beat well. Beat in as much of the flour mixture as you can. Stir in remaining flour mixture. From the chocolate dough into 32 balls about 1 1/4 inches in diameter. Set aside.

For filling: Combine powdered sugar and 1/2 cup peanut butter until smooth. Shape mixture into 32 ( 3/4-inch) balls.

On a work surface, slightly flatten a chocolate dough ball. Top with peanut butter ball. For each cookie, shape the chocolate dough over the peanut butter filling, completely covering the filling. Roll dough into a ball.

Place balls 2 inches apart on an ungreased cookie sheet. Lightly flatten with the bottom of a buttered glass dipped in 2 tablespoon granulated sugar.

Bake cookies in preheated oven for 8 minutes, or until just set and surface slightly cracks. Let stand 1 minute. Transfer to wire racks, cool. Makes 32.

To store: Place cookies in layers separated by waxed paper in an airtight container. Cover. Store at room temperature for up to 3 days or freeze for up to 3 months.

"Better Homes and Gardens Christmas Cookies 2002"