Preheat oven and line muffin tins with paper liners.
Prepare cupcakes according to box directions
Fill liners ⅔ full and bake according to box directions for cupcakes
Allow to cool completely.
Use a knife to dice apples into smaller pieces.
use a knife to core our a plug in the middle of each cupcake and fill with pie filling.
Place just the top of the plug back on the cupcake.
Whip butter, brown sugar, caramel syrup, and vanilla until fluffy.
Gradually add powdered sugar.
Add milk until you reach your desired consistency.
Transfer to a pastry bag and frost each cupcake.