Ingredients:

For the crust:.

1 1/2 cups all-purpose flour
1/2 cup unsalted butter, cold and cut into small cubes
1/4 cup granulated sugar
1/4 teaspoon salt
1 large egg yolk
2-3 tablespoons ice water

For the lemon filling:.

3/4 cup freshly squeezed lemon juice
1 tablespoon lemon zest
1 cup granulated sugar
3 tablespoons cornstarch
1/4 teaspoon salt
4 large egg yolks
1 1/4 cups water
2 tablespoons unsalted butter

Instructions:

1. Prepare the crust:

In a large mixing bowl, combine the all-purpose flour, granulated sugar, and salt. Add the cold butter cubes and use your fingers or a pastry cutter to cut the butter into the dry ingredients until the mixture resembles coarse breadcrumbs.

In a separate small bowl, whisk together the egg yolk and ice water. Pour the egg mixture into the flour mixture and gently mix until the dough comes together.

Transfer the dough onto a lightly floured surface and shape it into a disc. Wrap it in plastic wrap and refrigerate for at least 30 minutes.

2. Roll out the crust:

Remove the chilled dough from the refrigerator and let it sit at room temperature for a few minutes to soften slightly. Preheat your oven to 350°F (175°C).

On a floured surface, roll out the dough to about 1/8 inch thickness. Use a round cookie cutter or a glass with a diameter slightly larger than the tart molds to cut out circles from the dough.

Gently press each circle of dough into the tart molds, making sure to evenly distribute the dough and press it against the sides of the molds. Trim any excess dough hanging over the edges.

3. Bake the crust:

Place the tart molds on a baking sheet and prick the bottoms of the crusts with a fork. This will prevent the crusts from puffing up during baking.

Bake the crusts in the preheated oven for about 15-20 minutes, or until they turn golden brown. Remove them from the oven and let them cool completely.

4. Prepare the lemon filling:

In a saucepan, combine the granulated sugar, cornstarch, and salt. Gradually whisk in the water, lemon juice, and lemon zest until well combined.

Cook the mixture over medium heat, stirring constantly, until it thickens and comes to a boil. Let it boil for about 1-2 minutes, then remove it from the heat.

In a separate bowl, lightly beat the egg yolks. Gradually whisk in about 1/2 cup of the hot lemon mixture into the egg yolks to temper them. Then slowly pour the tempered egg mixture back into the saucepan, whisking constantly.

Return the saucepan to the heat and continue cooking the lemon filling, stirring constantly, until it thickens and reaches a pudding-like consistency.

Remove the saucepan from the heat and stir in the butter until completely melted and incorporated into the filling.

5. Assemble the tarts:

Once the tart crusts have cooled, spoon the prepared lemon filling into each crust, filling them to the top.

Smooth out the tops of the lemon filling using a spatula or the back of a spoon.

Chill the assembled tarts in the refrigerator for at least 2 hours, or until the filling is set.

6. Serve and enjoy:

Remove the chilled lemon tarts from the refrigerator. You can leave them in the tart molds or carefully remove them from the molds and place them on a serving plate.

These single-serve lemon tarts can be enjoyed as is, or you can dust them with a sprinkle of powdered sugar or top them with a dollop of whipped cream for an extra touch of decadence.

Serve the tarts chilled and savor each tangy and creamy bite.