How to Make It
Preheat the oven to 375°. In a small bowl, whisk the paprika with the oregano, cayenne and garlic powder. Spread on a rimmed baking sheet and toast in the oven for 2 minutes, until the spices are fragrant.
Put the butter in a shallow bowl. Dip the cut side of each carrot in the butter and then coat in the spice mixture, pressing to help the spices adhere; transfer to a plate.
In a large cast-iron skillet, heat the canola oil until shimmering. Working in batches if necessary, add the carrots cut side down in a single layer and season with salt and pepper. Cook over high heat until blackened on the bottom, about 2 minutes. Transfer the skillet to the oven and roast for 12 to 15 minutes, until the carrots are just tender.
Meanwhile, in a small bowl, whisk the vinegar and honey. Whisk in the olive oil, then season with salt and pepper. Transfer the carrots to a platter and drizzle with the vinaigrette.