Position a rack 6 inches from the broiler and heat the oven to 450°F. Line a large rimmed baking sheet with foil.
In a large bowl, toss the chicken thighs with the oil, 1 tsp. salt, and 1/2 tsp. pepper. Put a rack on the baking sheet and arrange the chicken thighs skin side up on the rack. Roast until the thighs are lightly golden and an instant-read thermometer inserted in the thickest part without touching the bone registers 165°F, about 20 minutes
Meanwhile, in a small saucepan, bring the cider and honey to a boil over high heat. Reduce the heat to medium and simmer vigorously until the mixture has reduced to 1/2 cup, 8 to 10 minutes. Remove from the heat and whisk in the butter.
Turn the broiler to high, brush the chicken thighs with the cider glaze, and broil for 1 minute. Brush with more glaze and broil again until deep golden-brown, 2 to 3 minutes. Remove the chicken from the oven, brush with more of the glaze, and serve.