Preheat oven to 350F (175C)
Make your chia eggs by combining the chia seeds with the water and setting them aside for at least 5 mins. They will be quite thick and gelatinous when ready.
In a large bowl whisk together the flour, pumpkin pie spice, baking soda, baking powder, and salt.
Make a well in the middle of the flour mixture and pour in the maple syrup, coconut oil and chia seed mixture. Mix together (but don't over-mix), gently fold in the pumpkin puree until everything is just combined.
Coat the inside of the doughnut pan with melted coconut oil to prevent sticking. Divide the mixture between 12 doughnut cups (you will have to do two loads if your pan only holds 6 doughnuts). Pop in the oven and bake for 20 minutes, until golden and a tooth pick comes out clean. Leave to cool completely in the pan.
To serve: melt some dark chocolate and dip the tops of the doughnuts in the melted chocolate (optional)
To store: store at room temperature or freeze