In a microwave-safe mug, combine the oat flour, cocoa powder, baking powder, and salt, mixing well to ensure no lumps.

Add the maple syrup, applesauce, almond milk, and vanilla extract to the dry ingredients. Stir until a smooth, thick batter forms.

Make sure to scrape the sides of the mug to incorporate all ingredients evenly.

Microwave the mug on high for 60-90 seconds, depending on your microwave's strength. The cake is done when the top is set but still slightly soft to the touch.

Allow the mug cake to cool for 1-2 minutes before serving. Optionally, top with fresh fruit, a dollop of Greek yogurt, or a sprinkle of nuts for added flavor.