Preheat the oven to 350° F.
Grease the doughnut pans and set aside.
To make the vegan buttermilk, stir together the plant based milk and lemon juice in a 2 cup measuring cup, set aside.
In a small bowl, mix together the powdered egg substitute to the package direction, and set aside.
Next, mix together the oat flour, cinnamon, salt, sugar, and oil in a small mixing bowl.
Continue by mixing in the egg substitute and vegan buttermilk into the small mixing bowl.
Stir until well combined.
Scoop the batter evenly into the prepared doughnut pans.
NOTE : If using silicone doughnut pans, place them onto cooling racks on top of a baking sheet before placing into the oven. (This is how I baked my doughnuts.)
Bake for about 20 minutes, rotate the pans in the oven and continue to bake for about another 10 minutes (Baking times can vary).
Check the doughnut by inserting a toothpick in a doughnut (if it comes out clean, they are done), but also test if the doughnuts are firm to touch.
I also checked by lifting a doughnut to see if it has slightly browned.
Once the doughnuts are done, remove from the oven and let them cool for about 15 minutes.
After they are cool, slide a knife around each doughnut, flip the pan to remove the doughnuts, and place them on a cooling rack.
Once the doughnuts are cool, add the topping of your choice.
I drizzled melted chocolate chips and peanut butter on my doughnuts.
Enjoy!