Combine orange juice, water, sugar, and honey in a large saucepan. Stir well to mix and bring to a simmer. Add vanilla, nutmeg, ginger powder, and lemon juice. Add the pears and simmer for 30 minutes, turning pears to make sure all surfaces have been cooked. Remove from pan and keep warm. Let the remaining liquid boil until syrup thickens. Cut pears into slices and arrange in a serving dish. Pour syrup over pears, garnish with mint leaves and serve.