Make the Tart Crust:

1. Preheat the Oven: Preheat your oven to 350°F (175°C).
2. Mix the Dough: In a food processor, combine flour, powdered sugar, and salt. Add the cubed cold butter and pulse until the mixture resembles coarse crumbs. Add the egg yolk and pulse again. Gradually add cold water, 1 tablespoon at a time, until the dough comes together.
3. Chill the Dough: Shape the dough into a disk, wrap it in plastic wrap, and refrigerate for at least 30 minutes.
4. Roll Out the Dough: After chilling, roll out the dough on a lightly floured surface into a 12-inch circle. Transfer it to a tart pan and press it into the edges. Trim any excess dough.
5. Blind Bake: Line the tart shell with parchment paper and fill with pie weights or dried beans. Bake for 15-20 minutes, then remove the parchment and weights and bake for an additional 5-10 minutes until golden. Let the crust cool completely.

Make the White Chocolate Filling:

6. Melt the White Chocolate: In a heatproof bowl, melt the white chocolate with the heavy cream over a double boiler or in the microwave. Stir until smooth and fully combined.
7. Add Butter and Vanilla: Remove from heat and stir in the butter and vanilla extract until the butter is melted and the mixture is silky smooth.
8. Fill the Tart Crust: Pour the white chocolate filling into the cooled tart crust and spread it evenly. Chill in the fridge for at least 30 minutes until set.

Prepare the Cranberry Topping:

9. Cook the Cranberries: In a small saucepan, combine the cranberries, sugar, and water. Cook over medium heat for 5-7 minutes, stirring occasionally, until the cranberries pop and the mixture thickens.
10. Add Orange Zest: If desired, stir in the orange zest for a hint of citrus flavor. Remove from heat and let the cranberry topping cool to room temperature.

Assemble the Tart:

11. Top with Cranberries: Once the white chocolate filling is set, spoon the cranberry compote over the top of the tart, spreading it out evenly.
12. Chill the Tart: Chill the tart in the fridge for at least 1 hour to allow the flavors to meld and the topping to firm up.