Peel and core your apple, then carefully slice into 1/16" slices with a knife or mandoline
Combine melted butter, sugar, and cinnamon in a medium mixing bowl
Coat each slice with melted butter mixture and stack in a ramekin until you reach the top
Press down on the layers a few times throughout stacking and pour out the excess liquid back into your bowl
Once you've reached the top of your ramekin, move to a 400°F oven for 10 minutes
After 10 minutes, carefully pour out the excess liquid in your ramekin and top your stack with a piece of puff pastry brushed with egg wash
Return to the oven for 20 minutes
Let it cool completely before serving
Loosen your stack from the ramekin with a butter knife, and serve upside down with ice cream
