Prepare the Peanut Butter Filling:

In a medium bowl, combine the creamy peanut butter and powdered sugar. Mix until smooth. Scoop the mixture into 12 equal portions and roll them into balls. Place these balls on a parchment-lined baking sheet and freeze until firm, about 15 minutes.

Make the Cookie Dough:

In a large bowl, beat together the creamy peanut butter, softened butter, brown sugar, and granulated sugar until the mixture is light and fluffy. Add the egg and vanilla extract, mixing until well combined.

Combine Dry Ingredients:

In a separate bowl, whisk together the all-purpose flour, baking soda, and kosher salt. Gradually add this dry mixture to the wet ingredients, mixing until just combined.

Assemble the Cookies:

Preheat your oven to 375°F (190°C) and line a baking sheet with parchment paper.

For each cookie, take a heaping tablespoon of cookie dough and flatten it into a round disc. Place a frozen peanut butter ball in the center and fold the edges of the dough around the filling, sealing it completely. Roll the dough ball in granulated sugar and place it on the prepared baking sheet, spacing them about 2 inches apart.

Bake:

Bake the cookies in the preheated oven for 12–15 minutes, or until the tops are dry and the cookies are lightly golden on the bottom.

Cool:

Allow the cookies to cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely.