Lightly coat a 10-ounce to 12-ounce microwave-safe ceramic mug with non-stick spray or coconut oil.

In a separate small bowl or directly in the mug, combine the pumpkin puree, maple syrup, melted coconut oil, almond milk, and vanilla extract; whisk until emulsified.

Incorporate the gluten-free flour, pumpkin pie spice, baking powder, and sea salt into the wet mixture.

Stir with a small spatula or fork until the batter is homogeneous, ensuring no dry flour pockets remain at the base of the mug.

Center the mug in the microwave and heat on 100% power for 90 to 105 seconds, or until the surface appears set and a toothpick inserted into the center comes out clean.

Extract from the microwave and allow the cake to rest undisturbed for 120 seconds to stabilize the internal crumb structure before consumption.