In a regular sized mug add melted coconut oil, pumpkin puree, maple syrup, vanilla extract, almond flour, coconut flour, pumpkin pie spice, and baking soda.
Add the lemon juice next, making sure it makes contact with the baking soda (this ensures your mug cake will bake up!)
At this point, mix the ingredients together well. Add in the egg and mix until completely incorporated into the cake batter.
Mix in a small handful of chocolate chips
Microwave for 2 1/2 minutes. Be careful because the mug will be hot! Drizzle peanut butter on top, sprinkle with extra pumpkin spice and enjoy!