Homemade Peanut Butter Cups

In 1-quart saucepan combine chocolate chips and shortening. Cook over low heat, stirring occasionally, until melted and smooth (3 to 5 minutes).
Loosen top paper cup from stack, but leave in stack for greater stability while being coated. With small paint brush, coat inside top cup evenly with about 1 teaspoon melted chocolate to about 1/8-inch thickness, bringing coating almost to top of cup, but not over edge. Repeat until 30 cups are coated; refrigerate cups.
In 2-quart saucepan combine butter or margarine and peanut butter. Cook over medium heat, stirring occasionally, until melted (4 to 6 minutes). Stir in confectioners' sugar and graham cracker crumbs. Press about 1/2 tablespoon filling into each chocolate cup.
Spoon about 1/2 teaspoon melted chocolate on top of filling; spread to cover. Freeze until firm (about 2 hours) carefully peel off paper cups. Store refrigerated.