Method:

• Heat oven to 350ºF. Line 13x9-inch pan with foil, leaving 1 inch of foil overhanging at 2 opposite sides of pan. In medium bowl, stir together cake mix and 1/2 cup pecans. With pastry blender or fork, cut in butter until mixture is crumbly. Lightly press in bottom of foil-lined pan. Bake 15 to 20 minutes or until set and just beginning to brown. Cool completely, about 30 minutes.
• In large bowl, fold sherbet into ice cream just until partially blended for marbled design. Spoon and spread over cooled crust. Cover; freeze until firm, at least 4 hours.
• Using foil handles, remove dessert from pan to cutting board 10 minutes before serving; peel back foil. Cut into 5 rows by 3 rows. Top each serving with whipped topping and sprinkle with pecans.