Thaw a sheet of frozen puff pastry, according to the directions on the package. Allow to thaw on counter for 40 minutes. Preheat oven to 400 degrees. Unfold the puff pastry and cut it into three strips along the fold marks. Bake on a lined baking sheet with parchment paper at 400 degrees for 15 minutes, until golden.
Allow puff pastry to cool while you make the whipped cream. Beat heavy cream until soft peaks form. Add maple syrup, sugar and vanilla and beat until stiff peaks form.
Thinly slice the peaches. Split each puff pastry in half lengthwise, so that you have six layers of pastry.Top two of the layers with 1/2 cup of whipped cream and 1/4 of the peach slices.Top with another pastry layer.Add another 1/2 cup of whipped cream and more peach slices.Top with a final pastry layer.Cut the two Peach Napoleons into three pieces for a total of six servings. Dust with powdered sugar and drizzle salted caramel topping on each. (Optional: sprinkle with nuts before serving).
Serve immediately after assembly or store in refrigerator for up to 4 hours.