I've been making these for years and they always turn out as long as you completely cool the brownies before spreading the creme de menthe and then agan before spreading the chocolate coating.
1 c. sugar
1/2 c. butter
4 eggs
1 c. flour
1 1/2 c. chocolate syrup
2 c. powdered sugar
1/2 c. butter
2 Tbsp. Creme de menthe
6 Tbsp. butter
1c. semisweet chocolate chips
Preheat oven to 350. Grease 9x13 pan. In large bowl, cream sugar and 1/2 c. butter. Beat in eggs one at a time, then stir in syrup. Stir in flour until blended. Spread in pan. Bake 25-30 min. In small bowl beat powdered sugar, creme de menthe and 1/2 c. butter until smooth. Spread evenly over COOLED brownies. Chill until set. In double broiler, melt 6 Tbsp. butter and chocolate chips. Stir often until smooth. Cool slightly, then spread over mint layer. Cover and chill 1 hour before cutting.