Preheat oven to 375 °F (180 °C). Lightly oil or spray an ovenproof 9" glass or ceramic deep-dish pie plate.
Peel pears, slice them, and arrange half the slices in the pie plate. Sprinkle with cinnamon and ginger. Place the rest of the slices on top.
In a small bowl, mix margarine, egg substitute, vanilla, and half and half (or light cream). Beat together until creamy. Set aside.
In a bowl, whisk together flour, baking powder, sugar substitute, and nutmeg. Add the wet ingredients. Use electric mixer to beat until almost fluffy. Spoon evenly over the pears, making sure all the pears are coated.
Bake for 45 to 60 minutes or until puffed and lightly browned.