Preheat your oven to 375°F (190°C). Line a loaf pan with parchment paper or lightly grease it.
In a large bowl, combine ground turkey, breadcrumbs, eggs, onion, garlic, ketchup, Worcestershire sauce, thyme, salt, and pepper. Mix gently with your hands until just combined - avoid overmixing.
Transfer the mixture to your prepared loaf pan and shape into a loaf. Brush additional ketchup on top.
Bake for 55-60 minutes, or until internal temperature reaches 165°F (74°C).
While the meatloaf bakes, place sweet potato cubes in a large pot and cover with water. Bring to a boil and cook for 15-20 minutes until tender.
Drain the sweet potatoes and return them to the pot. Add milk, butter, cinnamon, and salt.
Mash until smooth and creamy, adjusting seasoning to taste.
Let the meatloaf rest for 10 minutes before slicing and serving with the sweet potato mash.