Chocolate Tart

For the Crust:

1. In a food processor, combine the flour, cocoa powder, sugar, and salt. Add the cold cubed butter and pulse until the mixture resembles coarse crumbs.

2. In a small bowl, whisk together the egg yolk and ice water. Gradually add the egg mixture to the food processor, pulsing until the dough comes together.

3. Turn the dough out onto a lightly floured surface and knead it a few times to bring it together. Flatten the dough into a disk, wrap it in plastic wrap, and refrigerate for at least 1 hour.

4. Preheat the oven to 350°F (175°C). Roll out the chilled dough on a lightly floured surface to fit a 9-inch tart pan. Press the dough into the pan and trim any excess.

5. Place a sheet of parchment paper over the dough and fill it with pie weights or dried beans. Blind bake the crust for 15 minutes. Remove the parchment paper and pie weights, and bake for an additional 5 minutes. Set the crust aside to cool.

For the Filling:

1. In a saucepan, heat the heavy cream over medium heat until it just starts to simmer. Remove from heat.

2. Add the chopped chocolate, butter, vanilla extract, and salt to the saucepan. Let sit for a minute to allow the heat to melt the chocolate. Stir until smooth and well combined.

3. In a separate bowl, whisk the eggs. Gradually pour the chocolate mixture into the eggs while whisking continuously.

4. Pour the filling into the cooled tart crust. Smooth the top with a spatula.

5. Bake the tart for 20-25 minutes, until the filling is set but still slightly jiggly in the center.

6. Remove the tart from the oven and let it cool completely at room temperature. Then refrigerate for at least 2 hours before serving.

7. Serve the chocolate tart chilled, optionally topped with whipped cream or fresh berries.