Grease the inside of a standard loaf pan with cooking spray, set aside.
To a skillet, add the apples, 2 tbsp of cinnamon, and 2 tbsp of sugar.
Mix to combine and cook over medium heat until apples have softened.
Remove from heat and set aside.
Take each of the biscuits and peel the layers in half to have 16 thinner biscuits.
Brush butter on to one side of each biscuit.
Sprinkle each biscuit with the remaining cinnamon and sugar (evenly dividing the 4 tbsp between all biscuits).
Add a small layer of apples to one of the biscuits.
Top with another biscuit and layer with a small layer of apples.
Continue this until you have 4 biscuits total.
Turn them on their side and lay them in the loaf pan.
Continue this, doing a stack of 4 biscuits at a time to the loaf pan until all biscuits have been used.
Bake in the oven for 20-30 minutes (you need the middle part of the loaf to be fully cooked). You may need longer. Be sure the middle part of the loaf is fully cooked.
Remove from the oven and allow to cool for 5-10 minutes.
In a small bowl, combine the powdered sugar with water.