Crack the egg right into a microwave-safe mug and give it a quick whisk with a fork until it’s a little frothy. Add the Nutella next and stir it in until smooth, it might look thick at first, but it’ll come together.

Sprinkle in the brown sugar, then add the flour. Mix everything until you get a nice, lump-free batter.

Put the mug in the microwave and cook it for about a minute. The cake should rise and feel just set on top. If it’s still a bit soft in the center, microwave in short bursts of 10 seconds until done.

Let it cool briefly, then grab your spoon and dive into the warm, gooey goodness!