In a small saucepan, combine 4 tablespoons sugar, cornstarch and 3/4 cup orange juice; stir until smooth. Bring to a boil; cook and stir for 2 minutes until thickened. Remove from heat; cool to lukewarm.
Meanwhile, combine biscuit mix and remaining sugar in a bowl. Beat the eggs, milk and remaining orange juice; stir into dry ingredients just until moistened.
Pour the batter by 1/4 cupfuls onto a lightly greased hot griddle; turn when bubbles form on top of pancakes. Cook until second side is golden brown. Serve with orange sauce.