Perfect Peanut Butter Buttercream between two Tagalong Girl Scout Cookies make these Tagalong Peanut Butter Buttercream Sandwiches the perfect afternoon treat! Yesterday I made the most delicious Triple Chocolate Peanut Butter Cupcakes for my friend Margo.  I had about  1/2 cup of peanut butter buttercream left after frosting all the cupcakes and a few Tagalong Girl