Chocolate Mayonnaise Cake

Name: Chocolate Mayonnaise Cake
Prep time: 15 min
Cook time: 45 min
Total time: 1 h
Cuisine: American
Ingredients: 3 cups all-purpose flour*; 1 1/2 cups [brand:name] Extra Fine Granulated Sugar; 9 tablespoons cocoa powder; 1 tablespoon baking soda; 1 1/2 cups whole milk; 1 1/2 cups mayonnaise; 1 teaspoon vanilla extract; 1 cup (2 sticks) unsalted butter, softened; 1/3 cup cocoa powder, sifted; Pinch of salt; 5 cups [brand:name] Confectioners Powdered Sugar; 4 - 7 tablespoons milk (or evaporated milk)