Mexican Chocolate Brownies

Brownies:

½ cup all purpose flour
1 ½ teaspoons ground cinnamon
½ round disc Mexican chocolate, pulverized
1/8 teaspoon salt
6 ounces semi-sweet chocolate, chopped
¾ cup (1 ½ sticks) unsalted butter, diced, room temperature
4 large eggs
1 cup sugar
1 ½ teaspoons vanilla
1 cup chopped walnuts

Topping:

6 ounces semi-sweet chocolate, chopped
½ round disc Mexican Chocolate, pulverized
3 tablespoons unsalted butter, room temperature
2 tablespoons whipping cream

For brownies: Position rack in center of oven and preheat to 350°. Generously butter an 8x8x2 inch metal baking pan; dust with flour. Mix first three ingredients in small bowl. Stir chocolates and butter in top of double boiler set over simmering water until melted. Stir until smooth. Turn off heat. Let chocolate stand over water.
Using electric mixer, beat eggs and sugar in large bowl until mixture thickens and falls in soft ribbon when beaters are lifted, about 5 minutes. Beat in vanilla. Stir in flour mixture in 2 additions, blending well after each. Gradually add warm chocolate to egg mixture, beating until just combined. Stir in walnuts.
Pour batter into prepared pan. Bake brownies until top is set and tester inserted into center comes out with moist crumbs attached, about 35 minutes. Cool completely in pan on rack.

For topping: Whisk all ingredients in small saucepan over medium-low heat until melted and smooth. Pour evenly over brownies in pan.
Chill brownies until topping is set, about 2 hours. Cut into 16 squares.