Preheat oven to 350°F. Spray 8x8-inch baking pan with baking spray; set aside.
Place chocolate and butter in medium microwave-safe bowl. Microwave on HIGH about 1-1/2 minutes or until melted. Add chili powder, habanero powder, peel and concentrate. Blend well; set aside.
Place sugar and eggs in large bowl. Beat with electric mixer on medium-high 1 minute or until light colored. Gradually add flour while mixing on low just until incorporated. Add chocolate mixture; mix until well blended.
Spread batter evenly into baking pan. Bake 28 to 30 minutes or until wooden pick comes out clean when inserted in center. Cool on wire rack completely before frosting.
Place cream cheese, butter and concentrate in large bowl. Beat with electric mixer on medium-high 2 minutes or until creamy and smooth. Gradually add confectioners' sugar, beating until creamy and smooth. Frost cooled brownies. Garnish with additional grated orange peel, if desired.