Preheat oven to 375°. Cut pears in half, cutting through stem and bottom ends. Scoop out core and pulp, leaving a 3/4-inch shell. Cut about 1/4 inch from opposite side of pear, forming a flat base.
Stir together crushed granola bars and next 4 ingredients. Spoon mixture into pear shells, pressing to gently pack. Arrange pears in a 13- x 9-inch pan. Pour cider around pears in pan.
Bake at 375° for 25 to 45 minutes or until pears are tender, basting twice with pan juices.
Place pears on a serving plate. Add preserves to pan juices, and cook, over medium-high heat, stirring constantly, 5 to 6 minutes or until thickened. Serve pears with warm sauce and Greek yogurt.
Note: Baking times will vary greatly due to the ripeness of your fruit. Begin testing for doneness by inserting a wooden pick directly into the fruit (not granola mixture) after 25 minutes of baking. A wooden pick should be able to pierce the fruit easily with just a little resistance. Overcooking will lead to the fruit losing its natural shape and becoming mushy. For testing purposes only, we used Nature Valley Oats 'N Honey Crunchy Granola Bars.