Prepare the Crust: In a mixing bowl, combine the flour, powdered sugar, and salt. Add the cold butter and mix until the mixture resembles coarse crumbs. Stir in the egg yolk and ice water until the dough comes together. Press the dough into a tart pan, ensuring it's even across the bottom and up the sides. Prick the bottom with a fork.
Bake the Crust: Preheat the oven to 350°F (175°C). Bake the crust for 15-20 minutes or until lightly golden. Remove and let it cool.
Make the Salted Caramel: In a saucepan over medium heat, dissolve the sugar until it turns a deep amber color, swirling the pan occasionally for even melting. Once melted, carefully whisk in the butter until smooth. Gradually add the heavy cream while whisking constantly. Stir in the sea salt and vanilla extract. Remove from heat and let it cool slightly.
Assemble the Tart: Pour the cooled salted caramel into the baked tart crust, spreading it evenly. Refrigerate for about 30 minutes to let it set.
Prepare the Chocolate Ganache: In a separate saucepan, heat the heavy cream until it just begins to simmer. Pour it over the chocolate chips in a mixing bowl and let it sit for 2 minutes. Stir until the chocolate is fully melted and smooth, then mix in the butter until glossy.
Finish the Tart: Pour the chocolate ganache over the set salted caramel layer, smoothing it out with a spatula. Return the tart to the refrigerator for another hour or until set.
Serve and Enjoy: Once set, slice the tart into wedges. You can sprinkle additional sea salt on top for garnish if desired.
Notes
Sprinkle additional sea salt on top for garnish if desired.