Chocolate Mirror Glazed Cake

Name: Chocolate Mirror Glazed Cake
Prep time: 2 h
Cook time: 45 min
Total time: 2 h 45 min
Cuisine: American
Ingredients: 1 3/4 cups all-purpose flour; 1 1/4 cups granulated sugar; 3/4 cup cocoa powder (unsweetened); 1 1/2 teaspoons baking powder; 1 1/2 teaspoons baking soda; 1 teaspoon salt; 2 eggs (large, ); 1 cup whole milk; 1/2 cup vegetable oil; 2 teaspoons vanilla extract; 1 cup water (boiling); 3/4 cup granulated sugar; 1/2 cup water; 1/2 cup heavy cream; 1/4 cup cocoa powder (unsweetened); 2 teaspoons powdered gelatin; 1/4 cup water (cold); chocolate ganache; 1 cup heavy cream; 8 ounces semisweet chocolate (chopped); 1 tablespoon unsalted butter