Preheat the oven to 375 degrees F. Line a baking sheet with parchment paper.
Cook the sweet potato in the oven for 50-60 minutes or in the microwave for 5-10 minutes, until soft.
Cook the quinoa according to package directions. I usually like to do steps 2 and 3 in advance to save time later on.
In a medium-sized bowl, mash the sweet potato with a fork. Mix in the quinoa, parsley, onion powder, pepper and salt (if using).
Using your hands, form the mixture into 12 mini patties, packing the mixture so that it all sticks together. Place the patties on the prepared baking sheet about an inch apart. Brush the top of each patty with half the olive oil.
Place in the oven and bake for 10 minutes. Carefully flip the patties and brush with remaining olive oil. Cook for an additional 10 minutes. Allow to cool for about 10-15 minutes. The patties will firm up during this time.
Store in the fridge for up to four days or in the freezer for up to three months.