Contest-Winning Brown Sugar Angel Food Cake

Place egg whites in a large bowl; let stand at room temperature 30 minutes. Sift 1 cup brown sugar and flour together twice; set aside.
Place oven rack in lowest position. Preheat oven to 350u0b0. Add cream of tartar, vanilla and salt to egg whites; beat on medium speed until soft peaks form. Gradually add remaining brown sugar, about 2 tablespoons at a time, beating on high until stiff glossy peaks form and sugar is dissolved. Gradually fold in flour mixture, about 1/2 cup at a time.
Gently spoon into an ungreased 10-in. tube pan. Cut through batter with a knife to remove air pockets. Bake 25-30 minutes or until lightly browned and entire top appears dry. Immediately invert pan; cool completely, about 1 hour.
Run a knife around side and center tube of pan. Remove cake to a serving plate.
For toffee, line a
with foil; grease the foil with 1 teaspoon butter. Sprinkle pecans into prepared pan; set aside.
In a small heavy saucepan over medium-low heat, bring brown sugar and remaining butter to a boil, stirring constantly. Cover and cook 2 minutes. Cook and stir with a clean spoon until a candy thermometer reads 300u0b0 (hard-crack stage). Immediately pour into prepared pan. Sprinkle with chips; spread with a knife when melted. Refrigerate for about 1 hour or until set.
Frost cake with whipped topping. Finely chop half of the toffee; press onto cake. Serve with remaining toffee if desired. Store leftover toffee in an airtight container.