The Best Easy Chocolate Cake | America's Test Kitchen

Ingredients

• 1 1/2 cups unbleached all-purpose flour (7 1/2 ounces/213 grams)
• 1 cup sugar (7 ounces/198 grams)
• 1/2 teaspoon baking soda
• 1/4 teaspoon table salt
• 1/2 cup Dutch-processed cocoa powder (2 ounces/57 grams)
• 2 ounces (57 grams) bittersweet chocolate , chopped fine (see note)
• 1 cup fresh black coffee, hot
• 2/3 cup mayonnaise
• 1 large egg
• 2 teaspoons vanilla extract
• Confectioners' sugar (for serving; optional)