Alsatian Tart with White Cheese: A Creamy and Traditional Delight!

Start making the dough. In a large bowl, mix together the flour, sugar and salt. Add the cold butter cut into small pieces and rub your fingertips with the flour until it resembles coarse sand. Add the egg yolk and mix until the dough is smooth. If necessary, add a tablespoon of cold water to bind the dough.
Form the dough into a ball, wrap it in plastic wrap and refrigerate for 30 minutes.
Meanwhile, prepare the topping. In a large bowl, beat the cream cheese and sugar until smooth. Add the eggs one at a time, mixing well between each addition. Add the cornstarch, vanilla extract, lemon juice and zest, and sour cream. Mix until smooth.
Preheat the oven to 180°C (350°F).

Remove the dough from the refrigerator and roll it out onto a lightly floured surface to form a disc about 30 cm in diameter. Place it in a greased and floured tart pan, pressing the edges firmly. Prick the bottom of the dough with a fork to prevent it from puffing up during baking.
Pour the cream cheese filling over the prepared dough.
Bake for about 40-45 minutes, or until the topping is set and lightly browned around the edges. Let the cake cool to room temperature before rolling. You can serve it warm or cold, depending on your preference.