(For the crust: )
* 2 cups all purpose flour
* ½ cup powdered sugar
* ¾ cup cold unsalted butter, cubed
* 2 egg yolks
(For the filling: )
* 1 cup cream cheese
* ¼ cup white cheddar cheese
* 1 tbsp salted butter
* 1 tbsp lemon juice
* 1 ½ tbsp cornstarch
* zest of half a lemon
* 1 large egg
* ½ tsp vanilla extract
* ¼ cup powdered sugar
* ½ cup heavy cream, whipped
(For the egg wash: )
* 1 egg yolk
* 2 tbsp milk
1) To make the crust: In a bowl, combine flour, sugar, and butter. Mix until mixture looks like wet sand. Mix in the egg yolk. If the dough is too crumbly, add ice water, 1 teaspoon at a time. Form into a ball, wrap in plastic wrap and refrigerate for 30 minutes.
2) To make the filling: In a saucepan over medium heat, mix the cheeses and butter. Cook until the cheese has melted. Once the mixture has melted, add the lemon juice, cornstarch, lemon zest, egg, vanilla extract, and powdered sugar. Mix until well-combined. Let it cool down completely and then refrigerate for 4 hours or 1 day.
3) Roll out your dough on a well-floured surface a quarter of an inch thick. Make sure that the dough is an inch bigger than your pie mold to have enough dough to cover the sides of the mold.
With a fork, poke the bottom of the crust, to avoid bubbles while it is baking. Place in the refrigerator for 15 minutes.
4) Blind bake the crust, this ensures that your crust retains it shapes and prevent air bubbles from appearing. To do this place a large piece of parchment paper and fill with dry beans or rice and bake for 10 minutes. Carefully, take out the parchment paper with dry beans or rice and bake for 6 minutes.
5) Whip the cream and fold into the chilled cheese mixture.
6) Pre-heat oven to 380°F.
7) Prepare the egg wash: whisk together the egg yolk and milk.
8) Brush egg whites onto the prepared crust then add the cheese mixture by the spoonful. Brush a thin layer of egg wash on the top of the cheese mixture and the sides of the crust. Bake the cheese tarts for 7 minutes. Let cool 3 minutes and then serve.
9) Store in the refrigerator and toast for 30 seconds and then serve.