Preheat the oven to 350 degrees Fahrenheit.

In a mixing bowl combine the dry ingredients: flour, baking soda, and salt. Set aside.

In a separate mixing bowl, combine the butter and the brown sugar with a stand up mixer or a hand-held mixer. Mix until the ingredients are light and fluffy.

Then add in the peanut butter, egg and vanilla. Mix until these ingredients are thoroughly combined.

Reduce the mixer speed to low and gradually mix in the dry ingredients until they are just incorporated. Do not over mix.

Form the dough into round balls with a cookie spoon. Gently roll the dough in the granulated sugar.

Form the dough into a log shape and place on a baking sheet. Use a fork to make a criss-cross pattern onto the cookie and carefully pinch the center of the cookies to form them into a shape of a peanut.

Bake for 10-12 minutes until the cookies are lightly golden brown.

Cool on the baking sheet for 5 minutes and then move the cookies to a wire rack to cool completely.

In a medium bowl, cream together butter and peanut butter until smooth and fluffy

Gradually add powdered sugar, alternating with milk, beating after each additional until desired consistency

To assemble the cookies, spread approximately 1 tablespoon of the filling onto approximately half of the cookies and top with the remaining cookies.

Then they are ready to serve and enjoy!