Devil’s-Food Cake With Toasted-Marshmallow Frosting Recipe

Ingredients

• 1 1/2 cups (340 grams/3 sticks) butter
• 1 1/2 cups (354 milliliters) black coffee
• 1 cup (85 grams) Dutch-processed cocoa powder
• 1 1/4 cups (170 grams) finely chopped dark chocolate (about 72 percent)
• 2 packed cups plus 1 tablespoon (453 grams) light-brown sugar
• 1 tablespoon vanilla extract
• 1 teaspoon Diamond Crystal kosher salt
• 6 large eggs
• 3 large egg yolks
• 2 cups (255 grams) all-purpose flour
• 1 tablespoon baking soda
• 1 cup (226 grams) egg whites
• 1 3/4 cups (340 grams) sugar
• 1/2 teaspoon Diamond Crystal kosher salt
• 1/4 teaspoon cream of tartar
• 1/4 teaspoon vanilla extract