Preheat oven to 400 degrees. Use softened butter to grease each muffin cup. Press cinnamon rolls into each muffin cup, spreading them out as you work them up the sides to create a cavity for the apple filling. Try to avoid having too much dough at the bottom or you won’t be able to add enough apple pie filling.
Peel apples, slice them thin, and dice into 1" pieces. Mix together apples with remaining filling ingredients in a medium bowl. Heat in the microwave stirring occasionally until the brown sugar syrup thickens and apples soften, about 2 minutes. You can also do this in a saucepan on the stove.
Use a slotted spoon to scoop mixture, straining some of the excess syrup before placing into the cinnamon roll cavity. Fill them up to the top of the tin.
Mix together the streusel topping ingredients in a bowl until it comes together in big crumbs. Place handfuls mounded on top of the apple filling, covering most of the tops. Bake for 15 mins, covering loosely with foil for the first 5 minutes. Rotate pan halfway through.
As it bakes, whisk the icing ingredients until smooth. Let the rolls cool for 5-10 minutes then drizzle over the tops of the apple pie cinnamon rolls and enjoy!