Yield: 2 cakes 3 tablespoons peanut butter 1 large egg 1 tablespoon vegetable oil 1/4 cup milk 1/4 teaspoon pure vanilla extract 1/4 cup packed brown sugar 1/3 cup self-rising flour Pinch of kosher salt 2 tablespoons jelly 1. In a large mug, whisk together the peanut butter and egg with a fork. Stir in the oil, milk, vanilla and sugar. Add the flour and salt. Beat the batter with a fork until smooth. Divide the batter between two mugs. 2. Top each with a generous tablespoon of jelly. Microwave separately for 1 1/2 to 2 1/2 minutes each until risen and firm.