Prepare the Tart Crust:

1. Make the Crust Dough: In a food processor, combine the flour, powdered sugar, and salt. Add the cold cubed butter and pulse until the mixture resembles coarse crumbs. Add the egg yolk and pulse to combine. If the dough is too dry, add ice water, a teaspoon at a time, until the dough just comes together.
2. Chill the Dough: Shape the dough into a disc, wrap it in plastic wrap, and refrigerate for at least 30 minutes to allow it to firm up.
3. Roll Out the Dough: Once chilled, roll the dough out on a lightly floured surface into a circle about 12 inches in diameter. Carefully transfer the dough to a 9-inch tart pan, pressing it into the edges and trimming off any excess dough.
4. Blind Bake the Crust: Preheat the oven to 350°F (175°C). Line the crust with parchment paper and fill it with pie weights or dried beans. Bake for 10-12 minutes, then remove the parchment paper and weights and bake for an additional 5-7 minutes until golden brown. Allow the crust to cool completely.

Prepare the Meyer Lemon Custard:

5. Make the Custard Base: In a medium saucepan, combine the Meyer lemon juice, zest, and granulated sugar. Heat over medium heat until the sugar dissolves and the mixture is warm but not boiling.
6. Whisk the Egg Yolks: In a separate bowl, whisk together the egg yolks until smooth. Gradually add the warm lemon mixture into the egg yolks, whisking constantly to temper the eggs.
7. Finish the Custard: Return the egg mixture to the saucepan and cook over low heat, stirring constantly, until the custard thickens enough to coat the back of a spoon, about 5-7 minutes. Do not let the custard boil.
8. Add Cream and Milk: Once thickened, remove the custard from the heat. Stir in the heavy cream, whole milk, vanilla extract, and a pinch of salt. Allow the custard to cool slightly.

Assemble and Bake the Tart:

9. Fill the Tart Crust: Pour the cooled custard into the prepared tart crust, smoothing the top with a spatula. Bake the tart in the preheated oven for 30-35 minutes, or until the custard is set but still slightly wobbly in the center.
10. Cool the Tart: Allow the tart to cool to room temperature, then refrigerate for at least 2 hours to fully set.

Brûlée the Top:

11. Caramelize the Sugar: Just before serving, sprinkle an even layer of granulated sugar over the top of the tart. Using a kitchen torch, gently caramelize the sugar until it forms a golden-brown, crispy layer. Alternatively, you can place the tart under a broiler for 1-2 minutes to achieve the same effect.