Add oats to the bowl of a food processor. Process on high until the oats are ground into a coarse flour consistency, about 30-60 seconds. Transfer the oats to a mixing bowl and wipe out the bowl of the Food Processor, returning it to the base.
Peel the small sweet potato and slice it into quarters lengthwise. Using the shredding disk, feed the pieces of sweet potato through the opening in the lid, pushing them down using the food pusher.
Measure 2 cups of the shredded sweet potatoes and add them to the bowl with the oats. Wipe out the Food Processor bowl again and place it back on the base.
Whisk together the flaxseed meal and water and set this aside to thicken.
Add black beans, onion, garlic, and the lime zest and juice to the Food Processor. Pulse until the mixture comes together, with a few larger chunks still remaining and transfer it to the mixing bowl. To the mixing bowl, add quinoa and the flaxseed gel and stir to combine.
Season this mixture with salt, pepper, chili powder, cumin, coriander and cayenne pepper.
Shape the mixture into equal-sized burgers and place them on a parchment paper-lined baking sheet. Chill the burgers in the fridge for at least 30 minutes prior to baking.
For cooking, preheat the oven to 375 degrees F. Bake the burgers on the middle rack for 20 minutes. Remove and flip them overcooking for another 15-20 minutes more.
Remove from the oven and let cool for 5-10 minutes to let the burgers set.
Serve with guacamole, tomatoes, sprouts and buns!