Preheat oven to 350°. Grease 2 (9-inch) round cake pans, and dust with cocoa. Set aside.
Beat cake mix and next 7 ingredients at low speed with an electric mixer 1 minute; beat at medium speed 2 minutes. Fold in chocolate morsels and chopped pecans. Pour batter into prepared pans.
Bake at 350° for 30 to 32 minutes or until a wooden pick inserted in center comes out clean. Cool in pans on wire racks 10 minutes. Remove from pans to wire racks, and cool completely. Wrap and chill cake layers at least 1 hour.
Whisk together cream cheese frosting and canned dulce de leche in a small bowl until well blended. Set aside. Cut 6 turtle candies in half, and set aside for garnish. Dice remaining turtle candies.
Using a serrated knife, slice cake layers in half horizontally to make 4 layers. Place 1 layer, cut side up, on cake plate. Spread with 1/2 cup cream cheese frosting mixture; sprinkle with one-third diced turtle candies. Repeat procedure twice. Place final cake layer on top of cake, cut side down. Spread chocolate fudge frosting on top and sides of cake. Cover and chill in refrigerator until ready to serve. Just before serving, drizzle dulce de leche ice cream topping over top of cake. Garnish with remaining halved turtle candies and pecan halves. Store in refrigerator.