1. In a bowl, mix 1 1/2 cups flour, cornmeal, baking powder, and salt. With pastry blender or fingers, cut or rub in 5 tablespoons butter until largest lumps are 1/4-inch pieces.
2. In another bowl, beat to blend caramel topping, 1/3 cup half-and-half, and egg. Pour into flour mixture and stir just until moistened.
3. Pat dough into a ball. Knead on a lightly floured board just until smooth, about 10 turns; add flour to board as required to prevent sticking.
4. Pat dough into a 6 1/2-inch round. Cut into 8 wedges and place pieces about 1 inch apart on a nonstick or lightly buttered 12- by 15-inch baking sheet.
5. Brush shortcake wedges with remaining 1 tablespoon half-and-half. Combine pine nuts with sugar and cinnamon; gently pat onto shortcakes.
6. Bake in a 375° oven until dark gold, 22 to 25 minutes. Cool on a rack.
7. In a bowl, mix sweetened condensed milk, sour cream, and lime peel with lime juice to make lime cream.
8. Split shortcakes in half. Place each bottom on a dessert plate. Combine raspberries, blueberries, and blackberries and spoon equally over shortcake bottoms. Spoon lime cream over berries, then place shortcake tops on cream.