Cookie dough:
Instructions:
Preheat oven to 350°F. Lightly grease two baking sheets. You could also line with parchment paper.
In a bowl, whisk together flour, cocoa, baking soda and salt. In a large bowl, beat together sugars, butter, and peanut butter until light and fluffy. Add vanilla and egg, beating to combine, and then stir in dry ingredients, blending well.
For the peanut butter filling, stir together peanut butter and powdered sugar, in a small bowl until smooth. With floured hands, roll the filling into 1/2 inch balls.
Break off about 1 Tablespoon of the cookie dough, make an indentation in the center with your finger, and press one of the peanut butter balls into the center. Bring the dough up and over the filling, pressing it closed. Roll the cookie in the palms of your hand to smooth it out, forming a ball.
Dip the top of each cookie in granulated sugar and place on prepared baking sheets about 2 inches apart. Grease the bottom of a drinking glass and use it to flatten each cookie to about 1/2-inch-thick. Bake cookies for 7 to 10 minutes, until set. Remove them from the oven and cool on a cookie rack.
