Prepare a 10" baking plate or pie dish with a non stick cooking spray. Cut pears into bite size pieces. Spread pears out on baking plate. Using a food processor on a lower speed, chop up and mix together peel and juice of lemon, eggs, and sugar. Add milk and continue to mix. Add English muffins broken up in pieces and continue mixing. Pour this mixture over the pears. Bake in 350 degree oven for 55 minutes. Cool for 5 - 10 minutes on a cake rack. Unmold onto a serving dish and chill over night. Prepare Butterscotch sauce by melting 8 ounces butter. Mix in brown sugar and half and half cream. Continue to cook for 5 minutes. Stir until you dissolve the sugar and mixture is creamy. Add 2 teaspoon vanilla extract and stir. Whip cream and use to decorate pie. Serve the butterscotch sauce to the side.