1½ sticks (12 tablespoons) unsalted butter, chilled and cut into ¼-inch cubes, plus 1 tablespoon at room temperature for greasing the pan
6 cups (24 ounces) fresh cranberries
1¼ cups granulated sugar
½ cup maple sugar (or an additional ½ cup granulated sugar)
Zest and juice of 1 medium orange
1 teaspoon ground cinnamon
½ teaspoon ground ginger
½ teaspoon ground cloves
1/8 teaspoon freshly ground black pepper
1 whole star anise
2¼ cups all-purpose flour
¼ cup whole-wheat flour
½ cup confectioners' sugar
¼ cup dark brown sugar
½ teaspoon baking soda
1 teaspoon kosher salt
⅓ cup old-fashioned rolled oats
1. Preheat the oven to 425°. Grease a 9-inch square baking pan with 1 tablespoon of room temperature butter. Line the baking pan with a long sheet of parchment paper, letting the sides of the paper hang loosely over the pan edges to create a sling.
2. In a medium bowl, toss together the cranberries, granulated sugar, maple sugar, orange zest and juice, cinnamon, ginger, cloves, black pepper and star anise to combine. Spread the cranberry mixture onto a rimmed baking sheet and roast, stirring frequently so the sugar does not burn, until the cranberries are soft and begin to pop, 10 to 12 minutes. Remove the cranberries from the oven and reduce the oven temperature to 375°.
3. In a large bowl, whisk together the all-purpose flour, whole-wheat flour, confectioners' sugar, brown sugar, baking soda and salt. Use your fingers to cut the cold butter cubes into the flour mixture until pea-size pieces form. Spread two-thirds of the flour-butter mixture on top of the parchment paper in the prepared baking pan, pressing down firmly to create an even crust. Cover the crust with the cranberry mixture.
4. To the remaining flour-butter mixture, add the rolled oats and mix until combined. Sprinkle the crumbly oat topping over the cranberries, squeezing some of the mixture together to create large streusel-style knobs. Bake the cranberry bars until the topping is golden brown, turning the pan halfway through baking, about 35 minutes total. Cool completely in pan before grabbing a hold of both sides of the parchment sling. Lift from the pan and use a sharp knife to cut into individual bars.
Make ahead: The crust, crumble topping and the cranberry filling can be made and refrigerated in separate airtight containers for up to 3 days before baking.
Storing: The baked bars can be stored in an airtight container at room temperature for up to 3 days.