Preheat oven to 350°. Line bottom and sides of an 8-inch pan with aluminum foil, allowing 2 to 3 inches to extend over sides; lightly grease foil.
Microwave chocolate squares and butter in a large microwave-safe bowl at HIGH 1 1/2 to 2 minutes or until melted and smooth, stirring at 30-second intervals. Whisk in granulated and brown sugars. Add eggs, 1 at a time, whisking just until blended after each addition. Whisk in flour, vanilla, and 1/8 teaspoon salt.
Pour mixture into prepared pan.
Whisk together chile powder, maple syrup, cinnamon, 1/8 tsp. salt, and cracked pepper in a medium bowl. Stir in pecans. Sprinkle pecan mixture over batter.
Bake at 350° for 42 to 46 minutes or until a wooden pick inserted in center comes out with a few moist crumbs, shielding with aluminum foil during last 15 minutes of baking to prevent excessive browning, if necessary. Cool completely on a wire rack (about 1 hour). Lift brownies from pan, using foil sides as handles. Gently remove foil, and cut brownies into 16 squares.