Preheat oven to 400°.
Melt butter in a large nonstick skillet over medium-high heat. Add onion, celery, carrot, and garlic; sauté 5 minutes or until tender. Add brandy; cook 30 seconds. Stir in half-and-half, tomato paste, and clam juice; bring to a boil. Cook 4 minutes, stirring occasionally. Combine cornstarch and 1 tablespoon water. Add cornstarch mixture, parsley, salt, pepper, and shrimp to pan; cook 1 minute, stirring constantly.
Divide the shrimp mixture evenly among 4 (10-ounce) ramekins coated with cooking spray. Top each serving with 1/4 cup cracker crumbs. Arrange ramekins on a baking sheet. Bake at 400° for 10 minutes or until bubbly and lightly browned.