Bite-sized Frozen Mint Rounds

1 cup butter
2 cups sifted powdered sugar
4 ounces unsweetened chocolate, melted
4 eggs
2 teaspoons vanilla
1 cup finely crushed Thin Mint cookies

Beat butter and sugar until light and fluffy. Add chocolate,
eggs and vanilla, beating until well-combined. Divide the cookie
crumbs in half. Sprinkle one half of the crumbs on the bottom
of 16 cupcake papers in muffin tins. Spoon chocolate mixture
over crumbs and top with remaining crumbs. Freeze until firm.