• In a microwave-safe coffee mug (minimum size 1 cup/250ml), whisk with a fork oat, flour, quick oats, baking powder, and salt. If using old-fashioned oats, use all-purpose flour for the best texture.
• Whisk in almond milk, almond butter, avocado oil, vanilla extract, and maple syrup. The batter should be thick and liquid.
• Stir in vegan dark chocolate chips if desired, or keep the batter plain.
• Microwave on high power (800W+) for about 90 seconds or stop the microwave 10 seconds after you see the cake top drying. The mug cake will barely rise as there's no gluten. Remove from the microwave carefully. It is hot! Check the texture. It should be moist and soft, a bit crumbly if you use oat flour but cooked in the center. If it is not cooked to your liking after that time, return to the microwave and cook again in 10-second bursts until done. Note that the longer you microwave the mug cake, the denser and dryer it will be.
• Let the mug cake cool down for a few minutes before serving it in its mug.
• Serve with fruits, maple syrup, and dairy-free yogurt.

Baking option

• Preheat the oven to 350°F (180°C).
• Grease an oven-proof ramekin with oil, add the cake batter and bake for 12-15 minutes until cooked through. Insert a toothpick in the center to check the baking time. If clean, it's ready to remove from the oven and serve.
• Serve immediately with toppings of your choice.