Preheat oven to 375 degrees F (190 degrees C). Prepare pie crust according to package directions for a filled one crust pie. In a microwave-safe bowl, microwave chocolate chips until melted. Stir occasionally until chocolate is smooth.
In a large bowl, combine cream cheese, sugar, and flour. Mix with an electric mixer at medium speed until well blended. Add melted chocolate, eggs, and 1/4 cup liqueur. Mix well. Fold in 1 cup whipped topping. Pour filling into the pie shell.
Bake for 30 to 35 minutes, or until knife inserted in center comes out clean. Cool.
Combine remaining whipped topping, 1 tablespoon liqueur, and the food coloring. Spread over pie.