• Preheat the oven to 350°F. Line an 8x8 metal baking pan with parchment and set aside.

Make the shortbread dough.

• In the bowl of a stand mixer or in a large bowl using a handheld electric mixer, beat the butter, confectioner’s sugar, vanilla, and salt until smooth and well blended.
  1 cup unsalted butter, 1 cup confectioners' sugar, 2 teaspoons vanilla extract, 1 teaspoon fine sea salt
• Add flour and baking powder and mix until combined and dough comes together.
  2 ½ cups all-purpose flour, ¼ teaspoon baking powder
• Add ⅔ of the shortbread dough to the prepared baking pan and gently press it down using your hands to create an even crust. Place the remaining ⅓ shortbread dough in the fridge.

Par-bake the shortbread crust.

• Bake the crust for 18-20 minutes or until the edges turn lightly golden. Let the pan cool on a wire rack for 5 minutes before adding the other layers to the pan. (Prep the cranberry filling while the crust bakes.)

Make the cranberry filling.

• Add cranberries, sugar, cornstarch, orange zest, and orange juice to a sauté pan. Cook over medium low heat, stirring frequently to coat the berries and keep the mixture from burning, for about 15 minutes or until the berries start bursting. Let the mixture cool for 5 minutes.
  2 cups cranberries, ¼ cup granulated sugar, 1 ½ teaspoons cornstarch, 1 Tablespoon orange zest, 1 Tablespoon orange juice

Assemble and bake the bars.

• Pour the cranberry filling over the par-baked crust and use a spatula to spread the filling to the edges, covering the crust.
• Crumble the remaining shortbread dough over the cranberry filling.
• Return the pan to the oven and bake the cranberry shortbread bars for 25 to 30 minutes, or until the crumble topping is golden.
• Let cool before slicing and serving.