Preheat oven to 400°F.
Peel, core and slice pears.
Sprinkle with lemon juice to keep from browning.
Mix sugar and cornstarch in saucepan.
Gradually stir in boiling water.
Bring to boil; cook 1 minute stirring constantly.
Then add sliced pears.
Pour into 12 x 8 x 2 inch baking dish.
Dot with margarine, sprinkle with cinnamon.
Make up shortcake dough and drop by heaping teaspoonfuls on top of pears.
Bake about 30 minutes.