Place the thawed puff pastry on a sheet of parchment.
Use a rolling pin to roll out the puff pastry, smoothing out any creases.
Transfer the pastry on the parchment to a baking sheet.
Arrange the sliced apples into rows on the pastry. You want them to overlap. Make sure to leave some space around the edges of the pastry for the border.
Brush the apples with melted butter before sprinkling with sugar and cinnamon.
Bake for 25-30 minutes or until the apples are tender and the pastry is golden brown.
If you are adding the glaze, brush it over the top of the tart immediately after removing it from the oven, while it is still hot to create a gloss.
Allow the tart to cool slightly before cutting and serving.