Place the puffed pastry rectangles onto a baking pan that's been sprayed with nonstick spray or lined with parchment paper. Add the sugar, salt and lemon juice to the apples. Stir to combine. Allow to sit for a few minutes.
Arrange the apple slices on the pastry rectangles in a straight line, overlapping as you go. Bake until the pastry is puffed and golden brown, about 20 minutes.
Remove from the pan immediately and place on a serving platter. Serve with caramel sauce and chopped pecans.