Easy Pineapple Orange Cake is like a bite of sunshine, with mandarin oranges baked right into the cake and a creamy crushed pineapple frosting. Since it starts with a cake mix, it is wonderfully simple to make, and serving it cold makes it an especially refreshing finish for a summer barbecue or potluck.
In a large bowl, mix together 1 yellow cake mix, 15 ounces canned mandarin oranges including the juice from the can, 3 large eggs, and ¾ cup sour cream. Beat on medium speed for 2 minutes.
Transfer batter to prepared pan and bake for 25-30 minutes or until the center bounces back when lightly touched with a finger.
Cool completely.
To make the frosting, combine the 20 ounces canned crushed pineapple along with the juice from the can with the 3.4 ounce vanilla instant pudding mix in a medium bowl.
Fold in 8 ounces Cool Whip. Spread over cake.
Chill for at least one hour or overnight before serving.