Mix flour, sugar, cinnamon, pumpkin pie spice, baking powder, and salt in a mug.
Stir in milk, pumpkin, melted butter and vanilla extract until smooth, being sure to scrape the bottom of the mug.
Stir in chocolate chips, if desired.
Microwave for 70-90 seconds (until cake is just set, but still barely shiny on top).
Allow to rest in microwave for a few minutes before eating.
