Grease the inside of a 6-quart slow cooker thoroughly with butter.

Open the package of refrigerated cinnamon rolls and cut each roll into quarters.

Layer half of the cinnamon roll pieces in the prepared slow cooker and spoon half of the apple pie filling on top.

In a separate bowl, whisk together the eggs, heavy cream, brown sugar, vanilla extract, and ground cinnamon until smooth.

Pour the custard evenly over the layered cinnamon rolls and pie filling.

Cover the slow cooker and set it to LOW heat for 2.5 to 3 hours.

While the casserole cooks, prepare the icing by beating cream cheese and butter until smooth, then mix in heavy cream and powdered sugar.

Once cooked, drizzle the icing over the warm casserole and serve.