Make the cake according to the package directions replacing the water with milk and the oil with butter. Bake according to the directions on the package.
Meanwhile, mix the sweetened condensed milk and the caramel together until well blended. Set aside the caramel glaze.
Once the cake is cooked, allow it to cool for 5 minutes. Poke holes with a skewer or fork and then pour the caramel glaze over the cake. Place cake in fridge.
TO MAKE WHIPPED CREAM
In a stand mixer, take the heavy cream straight from the fridge and pour it into the stand mixer bowl.
Add 1/4 cup powdered sugar and whip on medium high speed until the mixture has soft peaks.
Set aside and keep refrigerated.
TO MAKE THE SPICED APPLES
Add butter to a large pan over medium heat. Once the butter has melted, add apple slices and cook for 5 minutes to soften the apples.
Add brown sugar, vanilla extract, apple pie spice and kosher salt to the apples and stir to combine. Continue to cook over medium heat until apples are soft, about 15 minutes.
In a small bowl, whisk together the cold water and cornstarch. Pour the cornstarch mixture into the apple mixture.
Once the apples are soft, turn up the heat to medium high and cook for 2-3 minutes to thicken the syrup. The apples and syrup will be ready once it reaches the same consistency as maple syrup. Allow to cool completely.
TO ASSEMBLE THE CAKE
Spread whipped cream over the chilled caramel glaze soaked cake.
Add the cooled spiced apples over the whipped cream.
Chill for at least 3 hours before serving. Refrigerate any leftovers covered for up to 3 to 4 days.
Notes
When starting with a box cake mix, I always use milk instead of the water and melted butter instead of the oil.Poke holes in the cake using a chopstick, fork, or wooden skewer. This is a fun task for kids.Before pouring the glaze on the cake, let it sit for 4-5 minutes. You want the cake to be warm but not right out of the oven hot.The cake is best made a day ahead so it has plenty of time to chill. To make this even easier to prepare: