2 cups semisweet chocolate chips
2/3 cup unsalted butter
4 eggs, at room temperature
1 cup granulated sugar
1 teaspoon vanilla extract
1/2 cup all-purpose flour, sifted
1 teaspoon baking powder
1/2 cup coarsely chopped pecans
1 cup semisweet chocolate chips

Grease a 13 x 9-inch baking pan; set aside. Preheat oven to 350 degrees F.

Melt chocolate chips and butter in top of a double boiler set over simmering water, stirring until smooth. Remove from heat. Beat together eggs and granulated sugar in a medium mixing bowl on medium speed. Add vanilla extract. Blend in melted chocolate mixture. Lower speed, and add sifted flour and baking powder; blend well. Fold in nuts and remaining 1 cup chocolate chips. Pour batter into prepared pan. Bake for 25 minutes. Cool completely.

Frosting
3 cups confectioners' sugar
3 ounces cream cheese, softened
1/4 cup unsalted butter, softened
6 to 8 tablespoons milk
1/2 cup crushed hard peppermint candy
Whole peppermint candies (optional)

Beat together confectioners' sugar, cream cheese, butter and 4 tablespoons of the milk in a large mixing bowl on medium speed of electric mixer until smooth. Add additional milk, one tablespoon at a time, to achieve desired spreading consistency. Stir in crushed peppermint candy. Spread topping over cooled brownies. Cut into bars. Top each brownie with additional whole peppermint candy, if desired.