Frango Mints are a Chicago specialty, sold exclusively at Marshall Field's. My mother brought this recipe to California, and we make it with Andes Mints (any after-dinner style chocolate mint would do), for lack of Frangos. These are very rich, dense brownies, so don't be surprised if they don't rise very much in the oven.
2 oz unsweetened chocolate
1/2 C butter
1 C sugar
1 tsp vanilla
1/2 C flour
1/8 tsp salt
1/2 C chopped mints (one package of Andes will do)
Preheat the oven to 350 degrees. Melt the baking chocolate and butter, and allow to cool slightly. Beat the eggs with the sugar until light and fluffy. Stir in the chocolate and butter mixture. Add the vanilla, flour and salt. Fold in the mints. Pour the batter into an 8" greased pan and bake for 20-25 minutes, or until a shiny crust has formed on top. Be careful not to overbake!! Allow to cool before cutting into squares.