Preheat oven to 350°F (175°C) and grease a 9-inch pie dish.
In a bowl, toss sliced apples with lemon juice, brown sugar, cinnamon, nutmeg, and cornstarch until evenly coated.
Cut cinnamon rolls into quarters. Press half of the pieces firmly into the bottom and slightly up the sides of the pie dish to form the base.
Spread the apple mixture evenly over the cinnamon roll base.
Arrange remaining cinnamon roll pieces over the apples, leaving small gaps.
Drizzle melted butter evenly over the top.
Bake for 35–40 minutes, until the top is golden and the apple filling is bubbling.
Warm the reserved icing slightly and drizzle over the pie while warm.
Let cool for 5–10 minutes before slicing.