In a large bowl, stir together flour, sugar and salt. Cut in butter until consistency of cornmeal. Pack into bottom of a 10-inch tart pan (or 9-inch spring form pan) and press up the sides of pan. Press crumbs firmly.
Arrange apples on crust in rows that suggest cutting portions. Combine sugar, cinnamon and nutmeg and sprinkle over the apples. Bake at 400 degrees for 15 minutes.
In a small bowl, beat egg yolks and stir in heavy cream and pure maple syrup. Pour over apples evenly and continue baking for an additional 30 minutes.
Serve with vanilla ice cream, if desired.