Yield: 1 large coffee cup cake 1 egg 3 tablespoons milk Pinch of salt 1 teaspoon fine ground espresso coffee or instant coffee granules 3 tablespoons granulated sugar 3 tablespoons cocoa powder 2 tablespoons vegetable oil 3 tablespoons Nutella 4 tablespoons flour Whipped cream and chocolate shavings, for serving 1. Whisk the egg with fork in a large coffee mug. Add milk, salt, espresso or coffee, sugar, cocoa powder and oil. Mix well. 2. Add Nutella. Mix well. Then stir in the flour. 3. Microwave on high for 2 1/2 to 3 minutes. 4. Cool, top with whipped cream and chocolate shavings.