Slice peeled carrots diagonally into 2-inch pieces. If any are thicker than 1 inch, slice them in half lengthwise so they roast evenly. You should end up with about 6 cups.
In a large bowl, whisk together olive oil, brown sugar, cinnamon (if using), salt, and pepper to taste (I add 1 tsp salt and 1/4 tsp pepper) until well combined.Add sliced carrots to the bowl and toss until they’re evenly coated. (Do this in a bowl and not on the sheet pan so carrots are evenly coated.)
Use a spatula to transfer the coated carrots (and any liquid) onto the sheet pan. Place cut sides down so they’re touching the tray. Roast carrots 15 minutes, remove them from oven, and toss them well. Space them out again and flip the cut sides down to touch the tray. Roast another 10–15 minutes or until carrots are nicely caramelized and tender. Remove from oven and toss once more.
Serve warm right out of the oven.
Video
Notes
Note 1: Use soft, fresh brown sugar so it mixes in smoothly. Hard or clumpy sugar won’t coat the carrots evenly.Storage: These carrots are best fresh, but leftovers can be stored in an airtight container in the fridge for up to 3 days.