Preheat oven to 425°F. Line a large sheet pan with parchment.
Mix meatballs: Combine turkey, egg, breadcrumbs, feta, jalapeño, cranberries, garlic, olive oil, salt, pepper, and onion powder. Roll into 16 meatballs.
Season veggies: Add Brussels sprouts + squash to the sheet pan. Toss with olive oil, garlic powder, salt, and pepper.
Add meatballs to the center of the pan.
Roast 22–25 minutes or until meatballs reach 165°F and veggies are caramelized.
Finish: Add feta, parsley, or a drizzle of balsamic glaze.
Divide into 4 containers for meal prep.