1. For the crust, combine the flour, powdered sugar and salt in the bowl of a food processor. Pulse a few times to combine. Add the cold butter. Pulse until butter is the size of small peas. Add the egg yolk. Pulse to incorporate. Drizzle in the water (a little at a time) until dough is crumbly but starts to hold together when pressed.
2. Empty dough onto a large piece of parchment paper. Press together, forming into a large disc. Refrigerate for 30 minutes. Remove from fridge. Lightly flour parchment paper and both sides of dough. Lightly butter a 9-inch tart pan with a removable bottom. Roll out dough large enough to fill the pan with excess on the sides. Press dough into pan, and trim around edges. Freeze for 30 minutes.
3. Preheat oven to 375° F. Crumple a piece of parchment paper, and place on top of dough. Add pie weights to fill the bottom and up the sides. Bake for 20 to 25 minutes until dough is golden. Press down any areas that puffed up during the baking process. Let cool.
4. Fill a large bowl with 1/2 cup water, lemon juice and 2 tablespoons of granulated sugar. Cut the apples from their core into 3 pieces. Stand an apple upright. Slice off the front face of the apple with a knife positioned near the stem. Turn the apple slightly, and slice off another one-third. Continue with remaining one-third. (The core should be shaped like a triangle after cutting.) Use a mandoline to evenly slice apple sections into 1/8-inch slices. Add slices to the water as you go. Repeat with remaining apples.
5. In an even layer, sprinkle the bottom of the baked tart shell with 1 tablespoon each of granulated sugar and flour. Starting at the outer edge of the crust, begin arranging apple slices in a tight circle. Overlap each slice about halfway over the previous slice. Stand the apple slices up with cut edges down and peel edges pointing up. Continue to layer around the tart, packing the rows tightly. As you move toward the center, use small slices to bend and tuck into each other. Roll the last few slices into a circle, and tuck into the center.
6. Sprinkle the remaining 3 tablespoons of granulated sugar over the apple slices and between them. Scatter the butter pieces on top. Bake the tart for 40 to 45 minutes, or until apples begin to brown on the edges and crust is a deep golden-brown. Let cool before serving.

Per Serving (1 slice): Calories: 360, Fat: 20 g (12 g Saturated Fat), Cholesterol: 75 mg, Sodium: 150 mg, Carbohydrates: 45 g, Fiber: 2 g, Protein: 3 g.