If you haven’t taken your puff pastry dough out of the freezer, do so now. It will take about 30 minutes on the counter to thaw to room temperature. Preheat your oven to 350 degrees Fahrenheit and prepare a muffin tray with nonstick spray.
Wash the apples, cut them in half lengthwise, and remove the core. Use a sharp knife or mandoline. Slice the apples thinly widthwise, keeping the open side of the apple down. You want paper thin slices (cut into ⅛ – inch slices). Note: if you are using a mandoline, please be careful as the gadgets are super sharp.
Put the thinly sliced apples in a medium bowl and add the juice of half a lemon. Gently toss the apples in the lemon juice, taking care not to break any of the slices.
In a small bowl, add 1-2 teaspoons of sugar and a small pinch of cinnamon to the apples and gently mix until well combined. Set aside the remaining sugar and cinnamon.
Melt the butter and brush it onto one side of each thawed puff pastry sheet. Mix the reserved sugar and cinnamon together and spread it over the buttered puff pastry side. Cut each puff pastry sheet into six even strips.
Place a few slices of apple along each of the puff pastry strips and fold them over so that the apple slices are in between.
Gently roll up the apple and pastry into a rose shape and place it in the prepared muffin cups. Repeat until all 12 roses are rolled up. Bake in the preheated oven for 25-30 minutes, or until golden brown.
Allow to cool for 10 minutes before removing from muffin pan and serving. Use a knife or an offset spatula if necessary to remove from the pan. Dust with powdered sugar before serving the beautiful puff pastry apple roses, if desired.