Place butter into a microwavable mug and heat until just melted. (roughly 20 seconds)
Add in the remaining ingredients; mix well with a fork until just combined
Once the batter is mixed place the spoonful of jam down into the batter to get a jammy center
Microwave for 45 seconds - 1 minute or until is firm on top. (Cooking time is based on my 1200W Panasonic Inverter Microwave so your timing might vary). Always keep a close eye on your mug while in the microwave so it doesn’t over flow or over cook.