Preheat the oven to 375 degrees F.
In a small bowl or cup, whisk together the orange and lemon juices, cumin, coriander, cayenne pepper and salt. Let stand for a minute or two before whisking in the oil.
Place parsnips in an oven-proof dish and pour the citrus-honey dressing over them. Mix well to combine. Cook for 45-50 minutes, basting from time to time, until the parsnips are golden and fork-tender.
Serve immediately, with an extra drizzle of olive oil and a sprinkling of salt, if desired.