Start by whisking together the egg yolk, heavy cream, and a splash of vanilla extract in a bowl until smooth.

In a food processor, combine the all-purpose flour, confectioners’ sugar, and kosher salt, then pulse in the chilled butter until the mixture resembles coarse crumbs.

Gradually add the egg mixture, blending until a dough forms. Shape the dough into a disk, wrap it in plastic, and chill for at least 1 hour.

Roll out the chilled tart dough on a lightly floured surface to a thickness of about 1/8 inch. Fit the dough into a 9-inch tart pan, pressing it into the edges, and refrigerate for 15 minutes.

Preheat your oven to 350°F (175°C), then bake the crust for 20-25 minutes until golden brown. Cool completely on a wire rack.

In a saucepan over medium heat, whisk together the fresh lemon juice, lemon zest, eggs, and honey. Cook until thickened and reaches 165°F, about 5 minutes.

Remove from heat and stir in the cold unsalted butter until fully melted and combined. Strain the lemon curd through a fine mesh sieve.

Pour the curd into the cooled tart shell.

Bake for an additional 10-12 minutes until the curd is slightly jiggly in the center but has set around the edges. Let it cool to room temperature.

Puree the blueberries until smooth, then strain to remove seeds. Mix the puree with honey and cornstarch and cook over medium heat until thickened, about 4 minutes.

Carefully pour the blueberry mixture over the cooled lemon curd, spreading it evenly.

Refrigerate the tart for at least 2 hours or until the blueberry layer is fully set.