Peel and grate the sweet potato and apple. Gently squeeze out some of the excess liquid from the apple and sweet potato with a clean kitchen towel or paper towel.
Add the grated sweet potato and apple to a large bowl. Add the eggs, cheddar cheese, panko breadcrumbs, garlic powder, sage (if using), and salt. Stir well until everything is evenly combined.
Heat 1-2 tablespoon olive oil in a large skillet over medium heat.
Scoop about 2 tablespoons of the mixture into the skillet for each fritter and gently flatten with the back of a spatula.
Cook for 5-6 minutes per side, or until golden brown and cooked through.
Transfer the fritters to a plate lined with paper towel and repeat with the remaining mixture, adding more oil to the pan as needed.
Let cool slightly before serving. Enjoy on their own or serve with plain Greek yogurt, sour cream, applesauce, or a favourite dip.