Double Chocolate Tart Recipe

Name: Double Chocolate Tart Recipe
Ingredients: For The Crust:; 1 1/2 cups all-purpose flour; 3/4 cup confectioners' sugar; 1/2 cup cocoa powder; Pinch salt; 9 tablespoons cold unsalted butter, cut into 1/4-inch pices; 1 large egg yolk; For The Filling:; 8 ounces semi-sweet chocolate, finely chopped; 1 tablespoon confectioners' sugar; 1/2 teaspoon instant espresso powder; 3/4 cup whole milk; 1/2 cup heavy cream; 1 large egg, lightly beaten; 1/2 teaspoon vanilla extract; 2 pints chocolate ice cream to serve on side (optional)