Place racks in middle and lower third of oven; preheat to 400 Degrees. Line 2 large rimmed baking sheets with foil. Divide 2 lb. medium carrots, peeled and halved lengthwise, and 2 lb. medium parsnips, peeled and halved lengthwise between baking sheets and spread out in a single layer on each. Drizzle 2 Tb. olive oil over carrot-parsnip mixture, dividing evenly, and season generously with salt and freshly ground black pepper; toss to coat.
2 lbs medium carrots, peeled and halved lengthwise, 2 lbs. medium parsnips, peeled and halved lengthwise, 2 Tb. olive oil, salt and freshly ground pepper to taste
Roast carrots and parsnips, tossing every 10 minutes or so and rotating baking sheets top to bottom halfway through, until tender and browned in spots 35-40 minutes.
Melt 1 ½ Tb. butter in a small saucepan over medium heat. Add 1 ½ Tb. honey and 1 tsp. balsamic vinegar; stir to combine.
1 ½ Tb. butter, 1 ½ Tb. Buzz Savories Honey, 1 tsp. balsamic vinegar
To serve, transfer roasted vegetables to a warm platter, drizzle honey glaze over, and toss to coat.
Do ahead: Roasted carrots and parsnips can be cooked 2 hours ahead. Tent with foil and let stand at room temperature. Reheat, uncovered in 350 Degree oven until warmed through 8-10 minutes.