Adapted from mrfood.com
(15-ounce) can crushed pineapple, undrained
(18.25-ounce) package yellow cake mix
(11-ounce) can mandarin oranges, drained
(12-ounce) container frozen whipped topping, thawed
(5.1-ounce) package vanilla instant pudding mix
Preheat oven to 350 degrees F. Drain pineapple, reserving juice; set pineapple aside. •Combine pineapple juice, cake mix, eggs, mandarin oranges, and mayonnaise in a large mixing bowl. Beat at medium speed with an electric beater until blended. Pour batter into a greased 9- x 13-inch baking dish. Bake 30 minutes or until a wooden toothpick inserted in center comes out clean. Cool in dish on a wire rack. •Combine drained pineapple, whipped topping, and pudding mix in a mixing bowl; beat at low speed until blended. Spread mixture evenly over cake. Cover and chill at least 1 hour before serving. Store in refrigerator.