Gather all the ingredients.
In a large microwave-safe mug, whisk together the flour, sugar, cocoa powder, baking soda, and salt.
Add the milk, canola oil, water, and vanilla extract.
Stir until the batter is smooth with no dry flour remaining.
Microwave on high for about 1 minute and 45 seconds, or until the center is fully cooked.
Allow the Easy Microwave Chocolate Mug Cake to cool for 1–2 minutes before serving.
Enjoy as is or top with whipped cream, ice cream, or chocolate sauce.