Preheat oven to 350°. Bake pecans in a single layer in a shallow pan 5 to 6 minutes or until lightly toasted and fragrant, stirring halfway through.
Line a 13 x 9" pan with parchment paper. Prepare angel food cake batter according to package directions. Pour batter into prepared pan.
Bake at 350° for 30 to 33 minutes or until a wooden pick inserted in center comes out clean. Cool in pan on a wire rack 10 minutes. Remove from pan to a wire rack and cool completely, about 30 minutes.
Meanwhile, dissolve coffee granules and 4 teaspoons hot water. Beat butter at medium speed with an electric mixer until creamy; gradually add sugar, beating until light and fluffy. Add coffee, and beat until spreading consistency.
Trim and discard edges from cake. Spread frosting on top and sides of each piece of cake; roll in pecans. Serve with ice cream, chocolate sauce, and caramel sauce. Makes 15 servings