Note: Prepare the cake mix according to the package directions using the ingredients listed on the box.
Instructions
Preheat the oven to 350°F. Lightly grease a 9x13-inch baking dish.
Prepare the cake batter according to the package directions. Pour the batter into the prepared baking dish.
Bake for 25 to 30 minutes, or until a toothpick inserted into the center comes out clean. Let the cake cool for about 10 minutes.
Using the handle of a wooden spoon or a thick skewer, poke holes evenly over the top of the warm cake.
In a small mixing bowl, whisk together the boiling water and orange gelatin until completely dissolved.
In a large mixing bowl, whisk together the instant vanilla pudding mix and cold milk until smooth. Gradually whisk in the dissolved orange gelatin until fully combined.
Slowly pour the pudding mixture evenly over the cake, using the back of a spoon to help guide the filling into the holes.
Spread the thawed whipped topping evenly over the cake.
Refrigerate for at least 1 hour, or until completely chilled.
Garnish with drained mandarin orange segments and fresh mint leaves, if desired, just before serving.
Christina's Notes
Poke the holes evenly across the cake so the orange filling is distributed throughout every slice.
Allow the cake to cool slightly before adding the filling. If the cake is too hot, the pudding mixture may become runny instead of setting properly.
Whisk the pudding just until smooth before adding the dissolved gelatin. Pour it over the cake while it is still pourable so it easily fills the holes.
Spread the whipped topping gently with an offset spatula or the back of a spoon to keep it light and fluffy.
Avoid oversaturating any one area of the cake, as too much filling in one spot can create gummy pockets.
Garnish with mandarin oranges and fresh orange zest just before serving for the freshest appearance and flavor.
This cake can be made 1 day in advance and kept covered in the refrigerator until ready to serve.
Store leftovers covered in the refrigerator for up to 4 days.
Freeze individual slices, without the mandarin orange garnish, for up to 2 months. Thaw overnight in the refrigerator before serving.