Step 1: Prepare the Shortbread Crust

1. Preheat your oven to 350°F (175°C). Line a 9×13-inch baking pan with parchment paper for easy removal.
2. Cream the butter, granulated sugar, and brown sugar using a hand or stand mixer until light and fluffy.
3. Add the egg and vanilla extract, mixing until fully incorporated.
4. Gradually mix in the flour, baking powder, cinnamon, and salt to form a crumbly dough.
5. Reserve 1 ½ cups of the dough for the crumble topping and press the remaining dough evenly into the prepared pan to form the crust.

Step 2: Make the Cranberry Filling

1. In a saucepan, combine the cranberries, sugar, cornstarch, orange zest, orange juice, and vanilla extract.
2. Heat over medium, stirring occasionally, until the cranberries soften and the mixture thickens, about 5–7 minutes. Remove from heat and let cool slightly.

Step 3: Assemble the Bars

1. Spread the cranberry filling evenly over the shortbread crust.
2. Crumble the reserved dough over the cranberry layer, ensuring even coverage.

Step 4: Bake the Bars

1. Bake in the preheated oven for 40–45 minutes, or until the top is golden brown and the filling is bubbling slightly around the edges.
2. Remove from the oven and allow the bars to cool completely in the pan.

Step 5: Add the Vanilla Glaze

1. Whisk together the powdered sugar, milk or cream, and vanilla extract until smooth. Adjust the consistency with more milk or powdered sugar if needed.
2. Drizzle the glaze over the cooled bars using a spoon or piping bag.