Prepare the Crust:

1. Make the 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 ice water, pulsing until the dough just comes together.
2. Chill the Dough: Turn the dough out onto a lightly floured surface and shape it into a disk. Wrap in plastic wrap and refrigerate for at least 30 minutes.
3. Roll the Dough: Once chilled, roll the dough into a circle large enough to fit your tart pan (about 10 inches). Press the dough into the pan, trimming any excess around the edges. Prick the bottom with a fork.
4. Blind Bake the Crust: Preheat the oven to 350°F (175°C). Line the crust with parchment paper and fill with pie weights or dried beans. Bake for 10-12 minutes, then remove the weights and parchment and bake for an additional 5 minutes, or until golden. Let it cool completely.

Prepare the Ganache:

5. Heat the Cream: In a small saucepan, heat the heavy cream over medium heat until it just begins to simmer (do not let it boil).
6. Melt the Chocolate: Place the chopped dark chocolate in a heatproof bowl. Pour the hot cream over the chocolate and let it sit for 2-3 minutes to soften. Stir gently until the mixture is smooth and fully combined.
7. Add Butter and Vanilla: Stir in the butter and vanilla extract until fully incorporated, and the ganache is glossy.

Assemble the Tart:

8. Fill the Crust: Pour the chocolate ganache into the cooled tart shell. Smooth the top with a spatula and refrigerate for at least 2 hours, or until the ganache is set.
9. Top with Pomegranate: Once the ganache is set, sprinkle the fresh pomegranate seeds on top of the tart, ensuring an even distribution across the surface.