Step 1

Preheat oven to 350 degrees. Coat a 9 x 13-inch cake pan with nonstick spray.

Step 2

Make the batter. Prepare the cake batter according the mix directions. Add in the drained mandarin oranges and mix well with a spatula. The oranges will break up a bit; this is fine.

Step 3

Bake. Pour the cake batter into the prepared pan and bake 25 to 35 minutes. Cool completely, in the pan, for at least 30 minutes.

Step 4

Make the topping. When the cake is cool, blend whipped topping and dry vanilla pudding mix in a large bowl. Carefully fold in pineapple and juice. Spread the topping gently over the cake (it will thick). Top with canned mandarin orange slices.

Step 5

Chill. Cover and chill at least 30 minutes before serving.