In a microwave-safe mug, add flour, sugar, cocoa powder, baking soda, and salt. Mix well.
Pour in milk, canola oil, water, and vanilla extract.
Stir until the batter is smooth with no dry pockets.
Clean the mug edges for even cooking.
Microwave on high for 1 minute 30 seconds (may vary slightly by microwave).
Check if the center is cooked through; if not, microwave for 10–15 seconds more.
Let it cool for 1 minute before serving.
Top with whipped cream, praline sauce, or serve with a cold milkshake.