Prepare two smaller mugs or one 12-ounce mug by greasing the inside. You can use vegetable spray, vegetable shortening, or melted coconut oil.
Combine the dry ingredients from the flour to the salt in a bowl and stir to combine.
Mix together the wet ingredients, including the water, oil, vanilla, and vinegar. Pour it into the flour mixture and stir until fully combined and no large lumps of flour are visible.
Single Mug: Spoon the batter into the mug and place it on a plate in the microwave. Add toppings if using, like chocolate chips.Cook for 60 to 90 seconds (depending on your microwave), until the center of the cake is set.
Two Mugs: Spoon the batter into two mugs. Place them in the microwave (no need to add a plate as these don't usually cook over). Add toppings if using. Cook for around 60 to 90 seconds, until the center of the cakes are set.
Let the mug (or mugs) sit in the microwave for a minute or two to cool. Then serve your mug cake as is or add a dollop of coconut whipped cream and a drizzle of vegan chocolate syrup.
Notes
This cake is amazing when freshly baked. However, it can keep for up to 2 to 3 days in the fridge.Cooking Tips: Cooking time will depend greatly on the size of the mug you use and your microwave. I used a 1200 watt microwave and cook these mug cakes for about 90 seconds on average.The power of your microwave has a big impact on the amount of cooking time required for your mug cakes. Most microwaves fall between 800 and 1200 watts. Here's how to understand how to make this mug cake based on your microwave:
Cook for 60 Seconds — Many mug cakes will be done at this point, especially if your microwave falls within the average 800 to 1200 watts.
Check for Doneness — If your cake has a little dome, or you can press your finger gently on the top and it springs back, your mug cake is done.
If you need to Cook it Some More — If your mug cake is not quite done yet, cook it for 15 more seconds. Check it again and repeat until it's done.