Begin by melting 1 cup of butter in a microwave-safe bowl.

In a large mixing bowl, combine 1 ½ cups of sifted flour, ½ cup of cocoa powder, ½ cup of powdered sugar, and a pinch of kosher salt. Mix thoroughly, then pour in the melted butter. Stir until the mixture forms a cohesive dough.

Press the dough evenly into the bottom and up the sides of a tart pan, then chill in the refrigerator for about 15 minutes.

Preheat your oven to 375°F (190°C). Once the crust has chilled, remove it from the refrigerator and bake for 12 minutes.

After the initial baking, beat one egg white and brush it over the hot crust to create a barrier. Return the tart shell to the oven for an additional minute to set the egg wash.

In a saucepan, heat 1 cup of heavy cream, ½ cup of corn syrup, and 1 teaspoon of vanilla extract over medium heat until it just begins to simmer.

Add 1 cup of semi-sweet chocolate chips to the warm cream mixture and let it sit for a few minutes.

Gently stir until fully combined and glossy.

In a separate bowl, whisk together 3 large eggs until well combined.

Gradually pour the warm chocolate mixture into the eggs, whisking continuously to prevent scrambling.

Carefully pour the custard into the pre-baked crust.

Reduce the oven temperature to 325°F (160°C) and bake for approximately 35-40 minutes, or until set but slightly jiggles in the center.

Once baked, remove the tart from the oven and let it cool to room temperature.

Melt some white chocolate and drizzle over the top of the tart.