Torta Di Polenta

Ingredients

• 2 ts Cornstarch
• 3 tb Margarine, softened
• 2 ts Vanilla
• 1 1/2 c Low-fat buttermilk
• 3/4 c Frozen raspberries, divided
• 3/4 c Frozen blackberries, divided
• 2/3 c Sugar
• 1/4 c Unsweetened orange juice
• 2 Egg yolks
• 1/2 ts Ground nutmeg
• 1 ts Baking soda
• Vegetable cooking spray
• 1 3/4 c Yellow cornmeal
• 3/4 c Flour
• 1/4 ts Salt
• 1/4 c Water
• 2 tb Chambord (raspberry liqueur)
• 1 ts Baking Powder
• 1 tb Sugar