Preheat oven to 400 degrees.
Core and thinly slice apples.
Mix the apples with ½ cup sugar in a bowl. Sprinkle 3 teaspoons of cinnamon on the apples and mix well.
Unroll a pie crust onto a baking sheet lined with parchment paper. Pile the apples in the center of the pie crust and turn the sides over. Brush the crust with the egg yolk.
Sprinkle the tart with the remaining sugar and cinnamon.
Bake for about 25 to 30 minutes or until apples are cooked and crust is golden.
Cool for 10 minutes before serving. Garnish with sugar and cinnamon if desired.
