FOR THE CAKE: - 1½ oz semi-sweet chocolate (chips or chopped bar) - ¾ cup hot water or brewed coffee - 1½ cups granulated sugar - 1¼ cups all-purpose flour (about 160 g) - ¾ cup unsweetened cocoa powder (preferably high quality) - 1 tsp baking soda - ½ tsp baking powder - ¾ tsp salt - 1 large egg - ⅓ cup vegetable oil - ¾ cup buttermilk, shaken - 1 tsp vanilla extract

FOR THE CHOCOLATE GLAZE: - 8 oz semi-sweet chocolate (chips or chopped bar) - ½ cup heavy cream - 1 tbsp granulated sugar - 1 tbsp light corn syrup (optional) - 2 tbsp unsalted butter - pinch of sea salt (optional)

TO FINISH: - small piece of chocolate for grating or shaving on top