In a food processor, pulse flour, sugar, and salt. Add butter and cream cheese and pulse till the mixture looks like coarse cornmeal, about 10 pulses.
Sprinkle with lemon juice and 1 tablespoon of ice water and pulse a few times till liquid is dispersed. Pinch a bit of the dough to see if it holds together; if not, sprinkle with the remaining ice water and pulse to combine.
Turn the dough out onto the countertop and gently press it into a ball. Flatten into a 6-inch disk, wrap with plastic wrap, and refrigerate for at least 30 minutes.
Preheat oven to 375ºF. Remove the dough from the refrigerator.
Roll into a 15-inch circle between two sheets of parchment paper. Remove the top parchment and move the dough round with the parchment paper to a baking sheet.
Toss apples with the sugar and cinnamon; and arrange apples overlapping in semicircles, starting about 3 inches in from the edge of the dough, placing the thicker sides of the apples facing out.
Fold the outer dough border up over the apple filling, pleating as needed, then use cupped hands to press the sides of the dough so it adheres to the apples.
Bake for 30 minutes, then brush the exposed crust with egg white and sprinkle the remaining sugar over the whole tart.
Bake until the crust is golden and the apples are tender about 30 more minutes.
Cool for 10 minutes, then slide the tart and parchment onto a cooling rack.
If you'd like, brush some apricot jelly or jam over the apples to give them a slight sheen.
Use a large spatula to remove the tart from the parchment onto a serving plate. Serve slices with vanilla ice cream or whipped cream.
