Fun, easy to make, soft, lightly crumbly homemade peanut butter sandwich cookies with a creamy peanut butter filling in a fun to eat peanut shell shape. These homemade nutter butter cookies are a favorite!
In a large mixing bowl, cream together butter and brown sugar. Add the egg and vanilla and beat until well combined. Add the peanut butter and mix to combine. Add the dry ingredients and mix until just blended.
Bake 10-12 minutes, until lightly browned on the edges and still soft in center. Allow cookies to cool on baking sheet for 5 minutes before removing to a wire rack to cool completely.
To assemble, add a scant tablespoon of icing to the bottom side of one cookie and spread it out. Add a second cookie to the icing so that the two bottom sides are facing the frosting. Repeat with remaining cookies.