Mint Ravioli Cookies

1/2 cup butter or margarine softened
1/2 cup shortening
1 cup sugar
1 egg
2 1/2 cups all-purpose flour
1 teaspoon baking powder
1/4 teaspoon salt
3 dozen foil-wrapped rectangular chocolate mints unwrapped
Beat butter, shortening, sugar and egg in large bowl with electric mixer on medium speed, or mix with spoon.
Stir in flour, baking powder and salt. Cover and refrigerate about 1 hour or until firm.
Heat oven to 400. Roll half of dough into rectangle, 13 9 inches, on lightly floured surface.
Place mints on dough, forming 6 uniform rows of 6. Roll remaining dough into rectangle, 13 9 inches, on floured waxed paper.
Place over mint-covered dough. Cut dough between mints with pastry wheel or knife; press edges of each "ravioli" with fork to seal.
Place 2 inches apart on ungreased cookie sheet. Bake 7 to 9 minutes or until light brown. Remove from cookie sheet to wire rack.