1Heat oven to 350°F (325°F for dark or nonstick pans). In medium bowl, mix crust ingredients.
2Press in ungreased 13x9-inch pan. Bake 8 minutes; cool 10 minutes.
1Position rack in bottom third of oven; preheat to 325°F. Line 8x8x2-inch metal baking pan with foil, pressing foil firmly against pan sides and leaving 2-inch overhang. Coat foil with nonstick spray.
2 Melt butter in medium saucepan over medium heat. Continue cooking until butter stops foaming and browned bits form at bottom of pan, stirring often, about 5 minutes.
3Remove from heat; immediately add sugar, cocoa, 2 teaspoons water, vanilla, and 1/4 teaspoon (generous) salt. Stir to blend. Let cool 5 minutes (mixture will still be hot).
4Add eggs to hot mixture 1 at a time, beating vigorously to blend after each addition. When mixture looks thick and shiny, add flour and stir until blended.
5Beat vigorously 60 strokes. Stir in nuts. Transfer batter to prepared pan.
6Bake brownies until toothpick inserted into center comes out almost clean (with a few moist crumbs attached), about 25 minutes. Cool in pan on rack. Using foil overhang, lift brownies from pan.
7Cut into 4 strips. Cut each strip crosswise into 4 brownies.
1Stir the coconut milk and maple syrup together in a small saucepan and bring to a gentle boil.
2Pour this mixture over the chocolate and stir until all of the chocolate is melted.
3Allow to cool to room temperature, stirring every 15 minutes or so until the chocolate has thickened into a spreadable frosting.