Combine the apple cider, honey, lemon juice, and vanilla in the saucepan and bring to a boil.
Distribute the butter pieces around the dish and arrange the pears in the dish. Pour the cider mixture over the pears. Cover the dish and bake in the preheated oven for 20 minutes, then remove the foil and bake until the pears are nice and tender, basting occasionally, about 30 minutes. Remove from the oven and let stand for 10 minutes.
In the medium bowl, stir together the Greek yogurt, honey, and vanilla extract. Serve over the warm pears.