Chocolate Hazelnut Tart with Caramel and Sea Salt

Name: Chocolate Hazelnut Tart with Caramel and Sea Salt
Ingredients: 1/3 cup sugar, scant; 4 teaspoon all-purpose flour; 2 eggs, beaten; 1 cup toasted, peeled, and chopped hazelnuts; 2/3 cup bittersweet chocolate, chopped; 2/3 cup corn syrup, scant; 4 teaspoon butter, melted; 1/2 teaspoon vanilla extract; 1/8 teaspoon salt; 1 tart shell, see recipe below or use refrigerated pie dough; Favorite caramel sauce, such as sundae topping; Coarse sea salt; 1 cup all-purpose flour; 2 tablespoon granulated sugar; 1/4 teaspoon kosher salt; 1 stick very cold unsalted butter, diced; 2 tablespoon ice water, or more as needed