Preheat oven to 350 degrees Fahrenheit. Prepare a 9x13'' baking dish with cooking spray.
In a large bowl, add cake mix, eggs, oil, and 1/2 cup of the reserved liquid from the oranges. Fold to combine, then beat for 3-4 minutes on medium until light and fluffy. Add 1.5 cups of the drained mandarin orange segments and mix until they are broken into small pieces.
Combine cake mix, eggs, infused olive oil, and 1/2 cup of liquid from oranges in mixer with beater attachment on low until combined, then mix 3-4 minutes on medium until light and fluffy. Add 1 to 1 and 1/2 cans of drained orange segments (save at least a 1/2 can of the orange segments to garnish the top of the finished cake) and mix on medium until fully incorporated and broken up.
Pour into prepared pan and bake for 25-30 minutes, or until a toothpick comes out clean when inserted in the center. Allow to cool on a wire rack.
For the topping, add whipped topping, crushed pineapple, pudding mix, and vanilla extract to a clean mixing bowl. Whip with a wire whisk until it's fully combined. Then, chill in the fridge until the cake has cooled.
Spread the chilled topping over the cooled cake, then top with the reserved mandarin orange slices. You can place them in rows, or in a sunshine pattern.
Chill for one hour before serving.
Notes
I included the original whipped cream frosting above. If you want something a bit richer and sweeter, I like a cream cheese frosting on this cake too! You will need to whip together: 8 ounces cream cheese, softened1 stick of butter (1/2 cup), softened1 teaspoon vanilla extract3-4 cups powdered sugar, add in increments until it's the consistency you want