sublimation paper and a cylindrical heat press to directly transfer … designs onto coffee mugs,” said a press release.

Time to find out. Without needing much encouragement, I volunteered to try out Ninja’s new coffee mug with Heatstore technology to discover if the wizardry worked. Here's how I got on.

After, divide the mixture between four small microwave-proof cups (roughly 200ml) or three larger mugs. Break the chocolate bar into chunks and push into the mixture, then microwave on high (800W ...