Peanut Butter Sandwich Cookies

My brother and I share the same fascination for peanut butter so I wanted to make something extra peanut buttery for the both of us.  These are extremely rich and heavenly and did I mention the filling tastes like reese's pieces.  I found a recipe online for similar cookies but I shortened it up a bit to make them semi-homemade.
Ingredients:

• 2 packages ready to bake peanut butter cookies
• 1 1/4 cup powdered sugar
• 3 tablespoons margarine
• 3 tablespoons heavy whipping cream
• 1/4 teaspoon vanilla
• 1/2 cup creamy peanut butter

Directions:  Bake cookies as directed.  In medium bowl cream together sugar and margarine.  Add vanilla, peanut butter, and whipping cream and stir until smooth.  When cookies are done and cooled spread filling onto half of the cookies, then place the other half of cookies on top to form a sandwich.
Cookers Note:  I think this would taste great with oatmeal or chocolate chip cookies as well.  If you really want to make then fancy dip half of the cookie in melted chocolate.