In a large bowl mix cake mix, water and oil by hand. Add pie filling and blend it in by hand.
Divide batter between 2 pans evenly. Level off in pans and bake both at same time. Bake 25 minutes or until tooth pick inserted in center comes out clean.
Allow to cool completely and then invert one pan onto plate so the flat side is up. Spread with frosting. Now invert other pan on a seperate plate and then turn over onto other half of cake so the flat side is now ontop of the frosting. Frost top and sides of cake and garnish with walnuts.