Liberally spray a small (4-ounce) microwave-safe cup, mug, or ramekin with cooking spray.
In a small bowl, whisk together the Sunbutter, sugar, baking powder, cream or coconut milk, egg, and vanilla until smooth. Pour into the prepared mug and microwave on full power for 60 to 75 seconds or until the cake has risen and is firm to the touch. Top with the jelly or jam, let cool, and serve.