Preheat oven to 350°F and line a 9×5-inch loaf pan with parchment paper. Parchment paper makes it easier to pull out once it’s baked.
Combine diced apples, butter, both sugars, and allspice in a medium saucepan. Cook until apples have browned and softened and sauce is thick. Set aside to cool.
Remove biscuits from can and peel apart layers until you have 16 biscuit halves. Spoon about a tablespoon of cooked apple filling onto each biscuit piece.
As you add the apple filling, stack the biscuits on top of one another, forming stacks 4-5 biscuits high.
Arrange biscuits in the loaf pan, carefully turning stacks on their sides as you do so. Make sure that plain biscuit is on each end of the loaf and that filling does not touch the pan. Any extra apple mixture that you have, pour on.
Cover with foil and bake for 30 minutes at 350°F. Remove the foil and continue baking for another 30 minutes, until golden brown on top and the biscuits are cooked in the middle.
Add the powdered sugar and milk to a medium mixing bowl and whisk until combined and smooth. Drizzle on top and enjoy!