2 tablespoons butter
2 tablespoons honey
1 egg, at room temperature
½ teaspoon vanilla
3 tablespoons brown sugar
4 tablespoons self-rising flour
1 pinch salt
Add the butter and honey to the mug, and microwave for 30 seconds or until melted.
Once the mixture is melted and has cooled slightly, add the egg, vanilla, and brown sugar. Whisk until smooth.
Add the flour and salt, and mix until well-combined with minimal lumps.
Microwave the mug on high for 1 minute before checking.
Test the cake by pressing gently on the top. It should spring back slightly. If it doesn't, continue to microwave in 10-second intervals until it does. Serve immediately.