Preheat your oven to 400 degrees F
Defrost your puff pastry according to the box directions.
On a large 15 by 20 baking sheet pan lay a sheet of parchment paper to cover the bottom of the pan.
Lay two pieces of puff pastry sheets on the parchment, overlapping them in the middle. I like to brush on a small amount of water to the center so that the dough connects and seals.
Slice your peaches and lay the peach slices out in a design directly on top of the puff pastry, leaving about an inch to an inch and a half of pastry dough all the way around the edge open.
Once the center is filled with peaches, fold up the edges around the peaches.
Add your egg to a small bowl and 1 tablespoon of water. mix well and then brush on the egg wash onto the edge of the pastry dough.
In another medium bowl add the softened butter, sugar and cinnamon. Mix togeher.
Spoon out the butter and place it on top of the peaches evenly.
Bake immediately in the oven for 22-25 minutes.
You want the crust to be nice and golden brown. If needed you can add more egg wash during the bake.
Make sure the bottom of the peach tart is browned as well. Nothing worse than a soggy bottom!
Let the peach tart cool for about 30 minutes. Serve this warm, room temperature or cold. I prefer it room temperature and my husband perfers it warm!
You can top with homemade whipped cream or enjoy some ice cream on the side!
Store on the counter covered or in the fridge in an airtight container.