Prepare a single pie crust according to separate instructions (see notes above) and chill for at least one hour.
Remove chilled pie dough from refrigerator and let it sit at room temperature for 15 minutes while you prepare the filling.
In a large mixing bowl, combine apples, maple syrup, and cinnamon. Mix until apples are evenly coated.
Roll out the dough and transfer to a parchment-lined rimmed baking sheet.
Beginning from the outside edge, arrange sliced apples in a circular pattern working your way toward the center, leaving a 1 1/2 inch border around the outside. Using a pastry brush, glaze apples with the excess maple syrup left at the bottom of the bowl.
Fold the edges of the pie dough in over the apples and check that all pleats are sealed in order to ensure that there are no leaks.
Place the galette in the refrigerator and preheat oven to 375°F.
Bake for 40-50 minutes or until crust is golden brown and apples are tender. Cool on a wire rack.