Prehet oven at 400 degrees.
Blend sugar, cornstarch, and cinnamon in a medium saucepan. Stir in peaches and lemon juice. Cook, stirring constantly, until mixture thickens and boils. Boil and stir 1 minute.
Pour into ungreased 2-quart casserole. Keep fruit mixer hot in oven while preparing biscuit topping.
For biscuit topping:
Combine in a bowl, flour, sugar, and baking powder. Add shortening and milk. Cut through 6 times; mix until dough forms a ball. Drop dough by 6 spoonfuls onto hot fruit.
Bake 25 to 30 minutes or until biscuit topping is golden brown. Serve warm with cream or ice cream.