Preheat oven to 350º

To make filling, mix peanut butter and powdered sugar together, and set aside

Next, combine flour, cocoa powder, baking soda, and salt in a small mixing bowl and set aside

In a larger mixing bowl, beat butter and sugar until light and fluffy

Add egg, and vanilla, and blend until combined

Stir in dry ingredients, until dough forms

Use a 1 oz/2 tablespoon cookie scoop to scoop out eight balls of cookie dough

Divide remaining dough into eight 1-1 ½ tablespoon balls

Flatten larger balls into discs and use thumbs to make an indentation in the center

Fill each indentation with a spoonful of peanut butter filling

Flatten smaller balls into discs, and top peanut butter filled cookies with them

Seal edges the best you can

Arrange on cookie sheet with at least 2 inches of space between each

Bake in center of oven for 12-14 minutes

Remove from oven and transfer to wire rack to cool