Add the butter and let it melt before adding the apple slices.
After adding the apples, sprinkle in the sugars and cinnamon. Stir to coat the apples and then top the skillet with a lid.
Let the apples cook for about 10 minutes, stirring occasionally until the apples are fully broken down and soft. You should be able to stick a fork into an apple slice and have it slide right off.
Serve immediately with scoops of vanilla ice cream.