Prepare cake batter and bake as directed on package for 2 (8-inch) round cakes, substituting square pans for the round pans if desired. Cool cakes in pans 10 min. Remove from pans to wire racks; cool completely.
Meanwhile, cook nuts and 3 Tbsp. sugar in nonstick skillet on medium-high heat 5 min. or until sugar is completely dissolved and nuts are evenly coated with sugar glaze, stirring constantly. Spread onto baking sheet sprayed with cooking spray; cool completely.
Cut apricots in half; discard pits. Cut fruit into thin slices. Reserve a few apricot slices for garnish. Beat cream cheese in medium bowl with mixer until creamy. Add remaining sugar; mix well. Gently stir in COOL WHIP, then remaining sliced apricots.
Cut each cake layer horizontally in half with serrated knife; stack on serving plate, spreading 3/4 cup COOL WHIP mixture between each layer.
Microwave fruit spread in microwaveable bowl on HIGH 20 sec. or until heated through; stir. Drizzle over cake; spread to completely cover top of cake, allowing excess fruit spread to drizzle down side.
Top cake with remaining COOL WHIP mixture. Garnish with reserved apricot slices. Break candied nuts into small pieces; sprinkle over cake.