Ingredients

• 1/4 cup self-rising flour
• 1/4 cup white sugar
• 1 egg
• 3 tablespoons vegetable oil
• 3 tablespoons milk
• 2 tablespoons unsweetened cocoa powder, or more to taste
• 2 tablespoons chocolate-hazelnut spread (such as Nutella®), or more to taste
• 1/2 teaspoon salt
• 1/2 teaspoon vanilla extract

Instructions

1. Stir self-rising flour, sugar, egg, vegetable oil, milk, cocoa powder, chocolate-hazelnut spread, salt, and vanilla extract together in a large mug until batter is smooth.
2. Cook in microwave oven on full power until the cake has risen in the mug and is set in the center, 1 1/2 to 2 1/2 minutes.