Combine dry ingredients in your mug: flour, sugar, cocoa powder, baking powder, and salt. Whisk thoroughly until smooth and evenly blended with no lumps.

Add milk, vegetable oil, and vanilla extract to the dry mix. Stir gently until a thick, glossy batter forms and the color turns into a deep chocolate hue.

Mix optional chocolate chips or chopped nuts into the batter, ensuring they’re evenly distributed.

Microwave on high for 1 minute 30 seconds to 2 minutes, until the cake has risen and the top is set but still moist in the center.

Let it cool for about 1 minute before diving in.