Rhubarb Raspberry Crostata

Name: Rhubarb Raspberry Crostata
Prep time: 35 min
Cook time: 50 min
Total time: 1 h 25 min
Cuisine: European, Italian, Mediterranean
Ingredients: 1 1/4 pounds (about 4 cups) chopped rhubarb, (trimmed, washed and dried, cut into 1/2-inch to 1-inch (12 mm to 2.5 cm) pieces); 6 ounces (170 g) fresh raspberries; 1/3 cup (65 g) sugar; 1/4 cup (28 g) cornstarch; 3 tablespoons cold water; Beaten egg or lactose-free milk, (optional); 1 batch Crostata & Tart Crust,