Hot Fudge Cake with Warm Chocolate Sauce

Name: Hot Fudge Cake with Warm Chocolate Sauce
Prep time: 15 min
Cook time: 40 min
Total time: 55 min
Cuisine: American
Ingredients: 1 cup all-purpose flour (125 g); ⅓ cup unsweetened cocoa powder (30 g); ¾ teaspoon baking powder (3 g); ¾ teaspoon baking soda (3.5 g); 1 cup granulated sugar (200 g); ¼ teaspoon fine salt (1.5 g); 1 large egg (room temperature); ½ cup whole milk (120 ml); 5 tablespoons unsalted butter (melted and slightly cooled (75 g)); 1 tablespoon neutral oil (15 ml); 1 teaspoon vanilla extract (5 ml); ½ cup boiling water (120 ml); 1 cup heavy cream (240 ml); 1¼ cups semisweet chocolate chips or chopped dark chocolate (7 oz / 200 g); Vanilla ice cream (optional)