Poke a few holes in a sweet potato and wrap in foil. Roast ~1 hour in 400F oven, or until softened throughout. Leave oven at 400F when sweet potato is done roasting.
Prepare flax egg by combined 1 tbsp flax + 2 tbsp water. Mix well and let set for 2 minutes before using.
Drain and rinse black beans. Pat with paper towel to remove excess water. Mash beans lightly, leaving some beans whole.
Combine all ingredients in a medium bowl. Stir together with a wooden spoon, until a cohesive mixture forms. It should be soft and able to hold shape in your hand. If it is crumbly, try adding ½ a flax egg. If it is too runny, add in more oats.
Oil a muffin tin. Spoon ¼ cup mixture into each tin for 10 sweet potato breakfast bites. Bake at 400 for 35 minutes, or until a toothpick inserted into a bite comes out clean. The muffins should be crispy on the outside and soft on the inside when done.