chocolate pb cake

I made this for my boss's birthday celebration. it turned out yummy!

Chocolate PB Cake

18 1/4 ounces devil's food cake mix
1 cup water
2 egg whites
2 tablespoons fat-free margarine
2 tablespoons honey roasted peanut butter
1/2 cup skim milk
1 cups Splenda

Combine cake mix, water and egg whites. Pour into 13x9 pan sprayed with cooking spray. Bake at 350* for 25-30 minutes. While cake is baking, combine margarine, pb, and milk in a small saucepan and heat until combined. Remove from heat and add Splenda. After removing cake from oven, poke with holes and pour pb mixture over cake. Chill 4 hours.
Yield: 16 servings. per serving= 161 Calories; 7g Fat (35.7% calories from fat); 3g Protein; 24g Carbohydrate; 1g Dietary Fiber; trace Cholesterol; 305mg Sodium. Exchanges: 0 Grain(Starch); 0 Lean Meat; 0 Non-Fat Milk; 1 1/2 Fat; 1 1/2 Other Carbohydrates.