Combine cinnamon, vanilla, cornstarch, peach nectar, and pineapple or peach juice in a saucepan over medium heat. Stir constantly until mixture thickens and bubbles.
Add sliced peaches to mixture.
Reduce heat and simmer for 5 to 10 minutes.
In another saucepan melt margarine and set aside.
Lightly spray an 8-inch square glass dish with cooking oil spray. Pour hot peach mixture into the dish.
In another bowl, combine pancake mix, flour, sugar, and melted margarine. Stir in milk.
Quickly spoon this mixture over peach mixture.
Combine nutmeg and brown sugar. Sprinkle mixture on top of batter.
Bake at 400° F for 15 to 20 minutes or until golden brown.
Serve warm with ice cream, yogurt or whipped cream.