Apple Cranberry Oat Crumble - Once Upon a Chef

Ingredients

• 1 tablespoon unsalted butter, (at room temperature)
• 2 cups rolled oats
• 1½ cups all-purpose flour (spooned into measuring cup and leveled-off)
• 1⅓ cups (packed) light brown sugar
• ½ teaspoon salt
• 1½ sticks (12 tablespoons) unsalted butter, (melted)
• 8 large baking apples, (peeled, cored and sliced ¼-inch (6-mm) thick)
• 2 cups (8 oz) fresh or frozen cranberries
• 1⅓ cups granulated sugar
• 2 tablespoons cornstarch
• 2 teaspoons ground cinnamon