Gather ingredients: Prepare all ingredients including flour, cocoa powder, baking soda, salts, sugars, butter, peanut butter, vanilla, egg, powdered sugar, and granulated sugar for dredging.

Preheat oven: Set your oven to 375°F (190°C) and line two baking sheets with parchment paper or lightly grease them.

Mix dry ingredients: In a medium bowl, whisk together the all-purpose flour, cocoa powder (Dutch-process or natural), baking soda, and salt.

Cream wet ingredients: In a separate large bowl, beat granulated sugar, brown sugar, softened butter, and peanut butter until light and fluffy.

Add flavor and egg: Mix in vanilla extract and a large egg to the creamed mixture, blending thoroughly.

Combine dough: Gradually fold the dry ingredients into the wet mixture until just combined, careful not to over-mix.

Prepare filling: Mix creamy or crunchy peanut butter with confectioners’ sugar until smooth. Shape into about 26 small 1-inch balls using floured hands or a teaspoon scoop.

Assemble cookies: Scoop approximately 1 tablespoon of dough, create a center indentation, place a peanut butter ball inside, and fold dough to seal completely. Roll into smooth balls.

Dredge and flatten: Roll each cookie ball in granulated sugar and place them 2 inches apart on the baking sheets. Flatten with a greased glass bottom to about ½ inch thickness.

Bake: Bake for 7 to 9 minutes, until cookies are set and fragrant, yet still soft in the center.

Cool: Transfer cookies to a wire rack to cool completely.