Preparation

• Preheat the oven to 350 degrees.

• Melt 1 cup of unsalted butter, reserving the remainder.

• In a large bowl, combine the melted butter, sugar and 2 teaspoons of vanilla. Stir in the duck eggs, one egg at a time.

• In a separate bowl, combine ½ cup of cocoa, flour, baking soda and salt.

• Pour the wet mixture into the dry mixture, stirring until blended.

• Pour the batter into a lightly greased 13-by-9-inch pan. Bake for 30 to 35 minutes.

• Meanwhile, make the frosting: Place ½ pound of powdered sugar in a mixing bowl and set aside, reserving the remainder.

• Melt the remaining ½ cup of butter in a heavy saucepan. Add 1 tablespoon of cocoa and the milk, and bring to a boil. Remove from heat immediately.

• Pour the butter mixture over the powdered sugar in the mixing bowl. Stir. Add 1 teaspoon of vanilla and additional powdered sugar until you reach your desired thickness.

• Allow the frosting to set for 1 hour before using.

• Allow the brownies to cool completely before frosting. For the best flavor, frost the brownies and let them rest, covered, overnight in the refrigerator.