Let ice cream or frozen yogurt stand for 15 minutes to soften. Stir in fresh chopped fruit, if using. Spread mixture evenly in a 15x10x1-inch baking pan. Cover and freeze until firm.

Preheat oven to 350 degree F. Beat butter in a large mixing bowl with an electric mixer on high speed for 30 seconds. Beat in granulated sugar, brown sugar, unsweetened cocoa powder, and baking powder until just combined. Beat in egg and vanilla until combined. Stir in melted chocolate. Beat in as much of the flour as you can with the mixer. Stir in any remaining flour.

Divide dough in half. Roll each portion of dough out on a lightly floured surface to 1/8-inch thickness. Cut with a 3-1/2-inch decorative cookie cutter. Cut out centers with a 3/4-inch decorative cookie cutter, if desired. Reroll any dough scraps. You should have a total of sixteen 3-1/2-inch cookies. Place cutouts on ungreased baking sheets.

Brush cookie tops with water and sprinkle with colored granulated sugar, if desired. Bake for 8 to 10 minutes or until edges are firm. Cool on cookie sheet for 1 minute. Transfer cookies to wire racks to cool completely.

To assemble, let ice cream or frozen yogurt stand for 5 minutes to slightly soften. Cut with the same 3-1/2-inch cookie cutter used for the cookies (will have 8 cutouts). Set out 8 of the cookies with the "wrong" side up. Place an ice cream cutout on top of each cookie. Top with a second cookie, pressing slightly to seal to ice cream.

Wrap each ice cream sandwich individually in plastic wrap; freeze at least 2 hours. Let stand at room temperature for 5 minutes before serving. Freeze for up to 1 month. Makes 8 sandwiches.

For an easier method, do not spread ice cream in pan. Refreeze after stirring in fruit until firm yet spreadable. Spread about 3 tablespoons of the ice cream on half the cookies and top with remaining cookies. Press together.Nutrition facts are based on 18 sandwiches.