Bake this moist cake for a potluck and it will be the talk of the party. Pistachio pudding mix colors the cake batter bright green.
Heat oven to 350 F. Coat two 9-inch round cake pans with nonstick cooking spray. Line bottom of pans with parchment or waxed paper and spray again.
In a large bowl, beat cake mix, pudding mix, eggs, vegetable oil and soda on medium-high speed for 4 minutes. Scrape down side of bowl after 2 minutes.
Equally divide batter between prepared cake pans. Bake at 350 F for 35 minutes, or until a toothpick inserted in the center comes out clean. Cool cake layers in pans on wire rack for 15 minutes. Turn cake layers out directly onto rack and cool completely.
In a large bowl, beat pudding mix and milk for 2 minutes on medium-high speed. Fold in whipped topping.
Place 1 cake layer on a serving plate and frost top with 1 cup of the frosting. Place remaining layer on top and frost top and sides. Garnish with chopped nuts. Refrigerate for at least 1 hour before serving. Store in refrigerator.