First, pre-heat the oven to 350 degrees F. Prep a muffin tin with 12 cupcake liners.
Then, using a hand grater or food processor, grate the sweet potatoes and onion. Squeeze out excess water from onions and sweet potatoes using a paper towel and transfer to a bowl.
In a separate bowl, whisk together eggs, melted butter, flour, salt, pepper and scallions until mixed well.
Add in potato mixture and combine. The mixture should be moist (ew) but not soggy.
Fill the cupcake lines evenly with the potato mixture.
Bake in pre-heated oven for 45-60 minutes until lightly browned on top and cooked though.
Top with Greek yogurt and more scallions!