Rhubarb-Cranberry Cobbler

Ingredients

• 2 cups granulated sugar
• 3 1/2 tbsp cornstarch
• 1/4 tsp ground cinnamon
• 1/4 tsp ground ginger
• 8 cups frozen rhubarb (about 2 pounds), unthawed
• 1 cup fresh or frozen cranberries
• 1/4 cup frozen concentrated cranberry juice cocktail, thawed
• 1/2 cup unsalted butter, room temperature
• 1 large egg
• 1 tsp vanilla extract
• 1/2 cup whole milk
• 1 cup all-purpose flour
• 1 tsp baking powder
• 1/4 tsp salt
• Vanilla ice cream