Step 1: Preheat your oven to 350°F (175°C). Grease and flour two 9-inch round cake pans to ensure your cake comes out easily after baking.
Step 2: In a large mixing bowl, whisk together the granulated sugar, cocoa powder, salt, baking powder, baking soda, and all-purpose flour until well combined.
Step 3: Add the vegetable oil, eggs, hot water, buttermilk, and vanilla extract to the dry ingredients. Use an electric mixer on medium speed to blend all the ingredients together until smooth.
Step 4: Divide the batter evenly between the prepared cake pans. Bake for 30-35 minutes or until a toothpick inserted in the center comes out clean. Let cool in the pans for 10 minutes.
Step 5: For the frosting, combine melted butter, cocoa powder, powdered sugar, vanilla extract, salt, and milk in a bowl. Mix until smooth and creamy.
Step 6: Once the cakes are cool, frost the top of one layer with frosting, place the second layer on top, and frost the top and sides.
Step 7: Serve with a dollop of whipped cream or a scoop of ice cream if desired. Enjoy!