Preheat the oven to 425 degrees f. Prepare a baking sheet with parchment paper. In mixing bowl, add the peaches, flour, cinnamon, salt, 2 tablespoons of brown sugar, and 2 tablespoons of white sugar.
Coat the peaches in the mixture, tossing until the dry ingredients are fully melted into them. Unfold the puff pastry on the parchment paper and create a 1 inch square border with a paring knife.
Transfer the peaches to the center of the pastry sheet. Spread the sliced peaches evenly throughout the sheet covered all areas except the edges where you create the 1 inch border.
Now fold each side of the square over the edge of the peaches to enclose the tart. Score the crust of the tart with whatever design you would like, then place in the oven to bake for 27 minutes.
Can drizzle with melted frosting when done and sliced, or a bit of honey, or warmed jam drizzled on top is nice.