1. To make the doughnuts: Preheat your oven to 350°F (180°C, or gas mark 4) and grease your doughnut pan. Combine the oat flour, sweet rice flour, cocoa powder, cane sugar, coconut flour, flax meal, baking powder, baking soda, and salt in a large bowl, mixing well. In another bowl, whisk together the milk, brown rice syrup, pumpkin puree, oil, and vanilla extract until well combined.