Step 1

In a roughly 12oz or 350ml size mug, add the nut butter or oil, vanilla extract, milk, and sugar. Stir until combined and smooth. You might need to squish the nut butter about a bit with the back of the spoon to break it down.

Step 2

Add the flour, baking soda, salt, and cinnamon and stir until combined, making sure to reach right down into the bottom of the mug as you stir.

Step 3

Put in the microwave uncovered. I recommend sitting the mug on a small plate the first time you make it in just in case you get the mug size a bit wrong and it overflows.

Step 4

The first time you cook it there will be a little trial and error because all microwaves are different. I suggest cooking it on full power for 1 minute then check it and cook in 5-second increments after that until done. My microwave is 1200w and takes 1 minute 5 seconds. You will know when it is ready because it will have puffed up in the mug, almost to the top. The top of the cake will be slightly damp (because it's microwaved), but if you give it a little poke with a fork you should see fluffy sponge underneath.

Step 5

Sprinkle generously with the cinnamon and sugar before eating immediately.