01 - Preheat the oven to 350°F.
02 - Combine cranberries, granulated sugar, orange juice, orange zest, and cinnamon in a saucepan. Cook over medium heat for 8 to 10 minutes, stirring occasionally until cranberries burst and mixture thickens. If thicker, stir in cornstarch dissolved in 1 tablespoon water and cook 2 additional minutes.
03 - Transfer the cranberry mixture into a small oven-safe dish or pie plate.
04 - In a bowl, combine flour, oats, brown sugar, salt, and cinnamon. Cut in chilled butter with a pastry cutter or fingers until mixture resembles coarse crumbs.
05 - Evenly sprinkle the crumble topping over the cranberry filling. Bake for 15 to 18 minutes until the topping is golden brown and crisp.
06 - Allow to cool slightly before serving. Use as a topping for pies, cheesecakes, yogurt, or breakfast oats.