1 pkg. Duncan Hines pineapple cake mix
1 box vanilla instant pudding (sm.) mix
1/2 c. oil
3 eggs
10 oz. 7-Up

Mix well all of above ingredients. Bake in three 9 inch cake pans in 350 degree preheated oven for 25-30 minutes. Let cool before icing.

ICING:

1 (20 oz.) can crushed pineapple, juice and all
1 1/2 c. sugar
3 tbsp. cornstarch
3/4 stick butter

Mix and stir while cooking until thick. Stack layers of cake with icing between layers and cover cake with icing.