Preheat the oven to 400 degrees F (205 degrees C).
Get out a large rimmed cookie sheet, roasting pan, whatever you want that'll fit 25 1.5" meatballs. No need to grease it (I had no issues with the meatballs sticking to my stainless steel roasting tray as a lot of liquid is released while cooking).
Cook the sweet potatoes. You can use whatever your preferred method is. I peeled and cut mine into about 3/4" slices (if your sweet potato is huge, you might want to cut it in half lengthwise first), steamed them in my Instant Pot for 5 minutes, did a quick release and let them cool for a few minutes. You can also just peel and cut them into chunks and boil until tender.
While they're cooking, add the garlic powder, onion powder, salt and pepper to a large mixing bowl (if you want to use your stand mixer to make these, that's the quickest / least messy way). Mix them and then add in (but no need to stir in) the coconut oil. Adding still warm sweet potatoes will melt the coconut oil, making it easier to combine.
Once the sweet potatoes are cool enough to handle, add them to the bowl and stir until combined with the seasoning + coconut oil. There should be no lumps of sweet potato. You can use a glass to smash them if that helps.
Then add in the ground chicken and mix until well combined. It'll be very sticky.
Roll into 1.5" balls. If you have issues, wash your hands and dry them well. Or use a 1.5 tablespoon cookie scoop. You can also refrigerate the mixture for a few hours, which firms it up a lot and makes rolling easier.
Place them on the baking sheet. They can almost touch. Bake for 20 minutes then turn on the broiler and broil for another 1-5. For me, 5 minutes was good. Depending on your oven, your meatballs may only need 1-2 minutes under the broiler. Please keep an eye on them and don't leave them while under the broiler!