Roll out the thawed puff pastry until it's about 1/4-inch thick. Using a small heart shaped cutter (about 3 inches at its widest point), cut out 4 heart shapes. Cut out another 4 hearts and using another heart shaped cutter, about 1/2-inch smaller, cut out the center of 4 hearts, leaving just the outsides of the hearts. Throw away the centers or reserve for another use.
Brush all the solid heart pieces with beaten egg. Then place a cut-out heart on top of each solid heart and brush with beaten egg. Using a fork, lightly pierce the pastry, (this will help prevent the pastry from bubbling as it bakes).
Transfer hearts to a sheet pan and place in the preheated oven. Bake until golden brown and fluffy. Usually around 10 minutes, depending on your oven.
Remove from the oven and allow to cool.
Peel, core and thinly slice the apples. In a large skillet over medium heat add the sugar and heat until sugar starts to turn a golden color, add the butter and apples and cook until apples are tender but not mushy, around 3 to 5 minutes depending on thickness of apples. Remove from heat.
To finish, place the cooked pastry heart in the center of each plate and spoon the cooked apples with the sauce over the hearts.
Top with a scoop of vanilla ice cream and gold leaf.