Best Tarte Au Chocolat

Ingredients

• ½ cup unsalted butter, at room temperature
• ½ cup icing sugar, sifted
• 3 large egg yolks
• 1 cup cake and pastry flour
• ¼ cup Dutch process cocoa powder
• 2 tbsp cornstarch
• ½ tsp salt
• ½ cup whipping cream
• ¼ cup unsalted butter, cut into pieces
• 8 ounce bittersweet chocolate, chopped
• ¼ cup sugar
• ½ cup hot, strong coffee
• 2 large eggs, at room temperature
• 1 tsp vanilla extract