1 (18.5 oz.) pkg. yellow cake mix without pudding
1 (11 oz.) can mandarin oranges, undrained
1/2 c. vegetable oil
1 (15 1/4 oz.) can crushed pineapple, undrained
1 (9 oz.) carton frozen whipped topping, thawed
1 (3 3/4 oz.) pkg. vanilla instant pudding mix
Combine cake mix, mandarin oranges, eggs and oil; beat 2 minutes at highest speed of electric mixer. Reduce speed to low; beat 1 minute. Pour batter into 3 greased and floured 9 inch round cake pans. Bake at 350 degrees for 20 to 25 minutes or until a wooden pick inserted in center comes out clean. Cool in pans 10 minutes; remove layers from pans and let cool completely.
Combine remaining 3 ingredients; beat 2 minutes at medium speed of electric mixer; let stand 5 minutes or until mixture is of spreading consistency. Spread pineapple mixture between layers and on top and sides of cake. Chill at least 2 hours before serving. Store in refrigerator. Yield 1 (3 layer) cake.