Preheat oven to 350°F and line a 12-count cupcake tin with paper liners. Set aside.
In a medium bowl, whisk together the water, vegetable oil, applesauce, eggs, and caramel sauce.
1 cup water, ⅓ cup vegetable oil, ¼ cup unsweetened applesauce, ¼ cup caramel sauce , 2 large eggs
Add the cake mix and cinnamon and stir just until no large lumps of flour remain.
13.25 ounces vanilla cake mix, ½ teaspoon ground cinnamon
Add the wet ingredients to the dry and mix just until no large lumps of flour remain.
Fold the shredded apple into the batter
1 cup peeled and shredded Granny Smith apple
Divide the batter between the cupcake wells making sure to fill each one ¾ of the way full.
Bake the cupcakes for 15-17 minutes, or until a toothpick inserted into the center comes out clean.
Remove the cupcakes to a wire rack to cool completely before icing.
For the Frosting
Add the butter and caramel sauce to the bowl of a stand mixer fitted with the paddle attachment. Beat on medium speed for 1-2 minutes, or until they are fully combined.
½ cup unsalted butter, ¼ cup caramel sauce
With the mixer on low, slowly add the powdered sugar. Once all the powdered sugar has been added, scrape down the sides of the bowl and then turn the mixer to high speed and beat until the frosting becomes light and fluffy.
2 cups powdered sugar
Transfer the frosting to a piping bag fitted with your choice of tip and frost as desired.
Notes
*Be sure to use unsweetened apple sauce. Sweetened varieties with added sugar, cinnamon, or flavoring will mess with the final flavor.**I recommend using tart green apples to balance the sweetness of this recipe. If using red apples, be sure to use a firm variety, like Honeycrisp.Tips:
Use a boxer grater to easily shred the apple. A zester is another option, but a box grater works best.
Gently fold in the shredded apple so that you don't incorporate too much air into the batter. This also prevents overmixing, which can lead to gummy cupcakes.
Cool the cupcakes completely before frosting them; otherwise, the frosting will melt off.
Add a bit of milk to the buttercream if it turns out too thick. Start with ½ tablespoon of milk and add more, if needed.
Make Ahead: Bake and cool the cupcakes a day in advance and store unfrosted in an airtight container overnight. Frost just before serving for the best texture and presentation.Storage: Store caramel apple cupcakes in an airtight container at room temperature for up to 2 days or in the refrigerator for up to 4 days.