3 tablespoons dark brown sugar 1 tablespoon smoked paprika 2 teaspoons ground cumin 1 teaspoon celery salt 1 teaspoon granulated garlic 1 teaspoon onion powder ¼ teaspoon cayenne pepper 1 tablespoon kosher salt, plus more 1 teaspoon freshly ground black pepper, plus more 1 pound small carrots, scrubbed, halved lengthwise 3 tablespoons olive oil ⅓ cup pecans ½ cup plain Greek yogurt 2 tablespoons buttermilk 1 tablespoon chopped dill 2 teaspoons fresh lemon juice, plus more for serving

Combine brown sugar, paprika, cumin, celery salt, granulated garlic, onion powder, cayenne, 1 Tbsp. salt, and 1 tsp. black pepper in a small bowl.
Cook carrots in a large pot of boiling, generously salted water until crisp-tender, about 4 minutes. Drain; transfer carrots to a medium bowl. Add oil and spice mixture and rub carrots to coat. Let sit at room temperature 1–3 hours.
Preheat oven to 350°. Toast pecans on a rimmed baking sheet, tossing once, until fragrant and slightly darkened, 10–15 minutes; let cool, then coarsely chop.
Meanwhile, mix yogurt, buttermilk, dill, and 2 tsp. lemon juice in a small bowl; season dressing with salt and pepper.
Prepare a grill for medium-high heat. (Or, you can use a grill pan over medium-high.) Grill carrots, cut side down, until they are lightly charred and sugar begins to caramelize and bubble, about 3 minutes.
Arrange carrots on a platter, drizzle with dressing and more lemon juice, and top with pecans.
Do Ahead: Dressing can be made 3 days ahead. Cover and chill