See for yourself how fast a batch of these disappear.

1 cup butter-flavored shortening
1 cup creamy peanut butter
1 cup sugar
1 cup packed brown sugar
3 eggs
1 teaspoon vanilla extract
3 cups all-purpose flour
2 teaspoons baking soda
1/4 teaspoon salt
FILLING:
1/2 cup creamy peanut butter
3 cups confectioners' sugar
1 teaspoon vanilla extract
5 to 6 tablespoons milk
In a large bowl, cream the shortening, peanut butter and sugars until light and fluffy.
Add eggs, one at a time, beating well after each addition after each addition. Add vanilla. Combine the flour, baking soda and salt; add to creamed mixture and mix well.
Make into 1-in. balls, 2 in. apart on ungreased baking sheets. Flatten to 3/8-in. thickness with fork. Bake at 375° for 7-8 minutes or until golden. Allow to cool.
Make filling:
In a large bowl, beat the peanut butter, confectioners' sugar, vanilla & enough milk to achieve spreading consistency. Spread on half of the cookies and top each with another cookie.
Makes about 3 dozen sandwich cookies.