Mint Chocolate Delights

Makes 24 sandwich cookies

1/2	cup (1 stick) unsalted butter, softened
1/2	cup granulated sugar
1/3	cup packed light brown sugar
1/3	cup semisweet chocolate chips, melted
1	egg, beaten
1/2	teaspoon vanilla
1-1/2	cups all-purpose flour
1/4	cup unsweetened cocoa powder
1/4	teaspoon salt
2-1/2	cups powdered sugar
1/2	cup (1 stick) unsalted butter, softened
1/4	teaspoon salt
1/2	teaspoon mint extract
3	to 4 drops red food coloring
2	to 3 tablespoons milk or half-and-half

For cookies, beat butter and sugars in large bowl with electric mixer at medium speed until creamy. Add melted chocolate, egg and vanilla; beat until well blended, scraping down bowl occasionally. Combine flour, cocoa and salt in small bowl. Gradually add flour mixture, beating until well blended. Shape dough into 16-inch-long log. Wrap in plastic wrap; refrigerate about 1 hour or until firm.
Preheat oven to 400°F. Lightly grease cookie sheets and line with parchment paper. Cut log into 1/3-inch-thick slices. Place slices on prepared cookie sheets. Bake 10 to 12 minutes or until set. Cool 5 minutes on cookie sheets. Remove to wire racks to cool completely.
For filling, combine powdered sugar, butter and salt in large bowl; beat until well blended. Add mint extract and food coloring; beat until well blended and evenly tinted. Add enough milk, 1 tablespoon at a time, to make filling fluffy. Spread or pipe filling on bottoms of half the cooled cookies. Top with remaining cookies.