These are simple and delicious. I made a few changes to the original recipe (found here).
4-5 Golden Delicious apples
1/2 teaspoon cinnamon
1/2 cup sugar
6 tablespoons butter, cut into 24 cubes
Preheat oven to 375 degrees (if baking immediately). Unfold sheet of puff pastry dough and roll out on a floured surface until quite thin (less than 1/8”). Use a biscuit cutter or other round cutter to cut out about one dozen 3” circles (you may have to kind of recut the shape with a knife in some places if it doesn’t cut through all the way). Place dough circles on a parchment lined cookie sheet to chill while you prepare the apples. Peel, core and slice the apples as thin as you can. A mandolin works well for this part but I just used my slicing blade on my food processor (not as pretty and even but just as tasty).
Assembly: Place a cube of butter and a little of the cinnamon sugar (about 1/2 tsp) in the center of each pastry round. Pile apple slices up in circles on the piece of dough placing largest apple pieces on the bottom and building up to about 2 or 3 inches tall. Place another cube of butter on top and sprinkle all liberally with the remaining cinnamon sugar. Now you can either freeze them to be baked later or bake them for 30 minutes or until golden brown.
*Personal notes: Make sure your oven rack is in the middle of the oven. If it is too close to the bottom the sugar burns. Also, you can bake these and then freeze them. Thaw and eat or thaw and heat if you want that warm-apple-pie-experience.