Heat the oven to 425°F and cover a baking sheet pan with parchment paper. The parchment keeps cleanup easy while the hot pan environment encourages browning.

Place the carrots in a bowl and coat them with the olive oil, kosher salt, and black pepper. Every piece should look lightly glossy rather than dry or heavily slicked with oil.

Spread the seasoned carrots across the prepared baking sheet in one even layer. Leave gaps between pieces so you hear a gentle sizzle instead of moisture quietly pooling beneath them.

Roast baby or garden carrots for 18 to 20 minutes, and roast larger store-bought carrots for 25 to 30 minutes. The carrots are ready when a fork slides into the thickest piece easily and the edges are browned.

Transfer the carrots to a serving dish and add parsley if desired. Serve while warm, when the centers are tender and the browned edges are at their best.