Ingredients CAKE Done Cooking spray 1/2   Cup sugar, divided 3/4   Cup water 1/2   Unsalted butter, melted and cooled 2 tablespoons   Egg yolks 3 large   Cake flour 2 ounces (about 1/2 cup)   Unsweetened cocoa 1/3 cup   TOPPING Sugar 2 tablespoon   Mint leaves...