Step 1

Preheat the oven to 350°Fahrenheit (175°C). Grease a 9x13-inch baking pan and line it with parchment paper.

Step 2

Make the cake: In a large bowl, combine the yellow cake mix, eggs, oil, mandarin oranges (including the juice), and orange extract (if using). Beat with an electric mixer, on medium speed until the batter is smooth and well combined.

Step 3

Pour the batter into the baking pan and spread it flat on top. Bake for 35-40 minutes or until a toothpick inserted into the center of the cake comes out clean.

Step 4

Remove the cake from the oven and leave it to cool fully to room temperature.

Step 5

Make the frosting: When the cake is cool, combine the thawed Cool Whip and instant vanilla pudding mix in a large bowl. Whisk until thoroughly blended and smooth. Fold in the well-drained crushed pineapple last.

Step 6

Spread the pineapple frosting evenly over the top of the cake and garnish with orange slices or mandarins, as desired.

Step 7

Chill until ready to serve. Then slice, serve, and enjoy!