Preheat oven to 375°F (190°C). Grease a baking dish.
Toss sliced sweet potatoes, squash, and carrots with 1 tbsp olive oil, salt, and pepper. Roast for 15–20 minutes until just tender.
Layer sweet potatoes on the bottom of the dish. Add some feta and walnuts.
Add a layer of squash, then carrots. Continue layering vegetables, feta, and walnuts until full. Finish with sweet potatoes on top.
In a saucepan, simmer cranberry juice, honey, and balsamic vinegar for 5–7 minutes until reduced to a glaze.
Drizzle ⅔ of the glaze over the lasagna. Cover with foil and bake for 30 minutes.
Remove foil, drizzle remaining glaze, and bake uncovered for 10–15 more minutes until golden and bubbling.
Let rest for 10 minutes before slicing and serving.
