1 cup sugar
1/4 cup milk
1 teaspoon vanilla
1 (1-ounce) square unsweetened baking chocolate, melted, cooled
3 cups all-purpose flour
1/4 cup unsweetened cocoa
3/4 teaspoon baking powder
1/4 teaspoon baking soda
4 cups powdered sugar
1 tablespoon vanilla
2 to 3 tablespoons milk
Food color, if desired
Combine 1 cup butter and sugar in bowl; beat at medium speed, scraping bowl often, until creamy. Add 1/4 cup milk, 1 teaspoon vanilla and egg; continue beating until well mixed. Add melted chocolate; mix well. Add flour, cocoa, baking powder and baking soda; beat at low speed until well mixed.
Divide dough in half. Shape each half into a ball; flatten slightly. Wrap each in plastic food wrap; refrigerate 2 hours or until firm.
Heat oven to 350°F.
Roll out dough, one-half at a time (keeping remaining dough refrigerated), on lightly floured surface to 1/8-inch thickness. Cut with floured 2 1/4- to 2 1/2-inch round cookie cutter. Place 1 inch apart onto ungreased cookie sheets. Cut out center of half of cookies with Halloween-shaped mini-sized (about 1-inch) cookie cutters. Bake 8-11 minutes or until set. Immediately remove from cookie sheets. Cool completely.
Combine all filling ingredients except milk and food color in bowl. Beat at low speed, scraping bowl often and gradually adding enough milk for desired spreading consistency. Add food color, if desired.
Spread 2 teaspoons filling onto bottom of 1 cookie; top with cut-out cookie, bottom-side down. Repeat with remaining cookies and filling.
Mini-sized cutters can also be called small cookie or canapé cutters. They are often sold as a set of 8 or 10 shapes inside a round tin.
Bake small center cut-outs at 350°F, 4-5 minutes or until set.