1 1/2 cups butter, melted
1 cup unsweetened cocoa powder
3 cups sugar
4 large eggs
2 cups flour
1/2 tsp. salt
1 tsp. vanilla extract
3 (4.67 oz. boxes) Andes mints

Preheat oven to 350. Line a 9×13 baking pan with heavy-duty aluminum foil. Lightly grease. In medium bowl, combine melted butter and cocoa, stirring well; set aside.

In large bowl, beat sugar and eggs at medium speed with an electric mixer until fluffy (about 5 minutes.) Slowly beat in butter mixture. Add flour, salt and vanilla, beating just until combined. Spread half of chocolate mixture into prepared pan. Place mints, side by side, in an even layer over chocolate mixture, completely covering chocolate mixture. Carefully spread remaining chocolate mixture over mints, sealing to edges. Bake for 35 minutes. Let cool completely in pan.