Begin by preparing the crust and crumble for your Cranberry Crumble Pie Bars. In a large mixing bowl, combine the all-purpose flour, granulated sugar, and salt, mixing well to ensure an even distribution of the ingredients. Next, take the cold, cubed unsalted butter and cut it into the dry mixture using a pastry cutter or fork until it resembles coarse crumbs, about 5-7 minutes. Then, add the egg, milk, and vanilla extract, mixing until just combined and a dough forms.
Now it’s time to assemble your base. Preheat your oven to 350°F (175°C) and line a 9x13 inch baking pan with parchment paper for easy removal. Press half of the crust mixture firmly into the bottom of the prepared pan, creating an even layer. Make sure the layer is smooth and compact; this will be the foundation for your delicious cranberry filling.
To prepare the filling, grab a medium-sized bowl and combine the fresh or frozen cranberries, granulated sugar, orange zest, and orange juice. Use a fork or a potato masher to roughly crush the cranberries; this should take about 2-3 minutes. Once everything is mixed thoroughly, spread the cranberry mixture over the crust in the baking pan, ensuring it's evenly distributed for balanced flavor in your Cranberry Crumble Pie Bars.
Next, sprinkle the remaining crust mixture over the cranberry filling evenly. To add an extra layer of flavor, sprinkle the sliced almonds on top of the crust. Bake in your preheated oven for 35-40 minutes, or until the top is golden brown and the filling is bubbling around the edges. The almonds should be lightly toasted at this point, contributing a delightful crunch to your pie bars.
Once baked, remove the pan from the oven and let your Cranberry Crumble Pie Bars cool in the pan for at least 30 minutes. This allows the filling to set properly. After cooling, carefully lift the bars out using the parchment paper and slice them into squares. For an extra touch, drizzle with the optional orange icing made from confectioners' sugar and orange juice before serving. Enjoy the perfect bite of holiday cheer!