Preheat your oven to 350°F (175°C). Line an 8×8 inch baking pan with parchment paper, leaving a bit overhang for easy removal.

In the bowl of a stand mixer fitted with the paddle attachment, cream together the butter and both sugars until light and fluffy — about 3 minutes. Scrape down the sides of the bowl.

Add the egg and vanilla; mix until well combined. Scrape the bowl again.

In another bowl, combine the flour, baking powder, cinnamon, and salt by whisking until evenly mixed.

Add the dry mixture to the wet ingredients and stir just until the dough begins to pull away from the sides. Do not overmix.

Scoop out roughly 2 cups of dough (loosely packed) and set aside — this is your topping. Press the remaining dough evenly into the prepared pan, using your hands or the flat bottom of a measuring cup.

Bake for 15 minutes, or until the edges are just beginning to turn golden brown and the center is slightly set. Do not overbake. Remove from oven and let the crust cool slightly.

Meanwhile, prepare the cranberry filling: In a large bowl combine cranberries, sugar, cornstarch, orange zest, orange juice, and vanilla. Stir until berries are evenly coated.

Pour the cranberry filling over the warm crust, spreading gently so the layer is even.

Take the reserved dough and break it into small pieces with your fingers. Sprinkle these crumbs randomly over the cranberry layer, leaving small gaps so berries peek through.

Return the pan to the oven and bake for about 45 minutes. During the last 10 to 15 minutes, tent a sheet of aluminum foil loosely over the top to prevent the crumbs from over‑browning.

Once baked, remove the pan and place it on a wire rack to cool completely before glazing.

To make the vanilla glaze, whisk together powdered sugar, milk (or cream), and vanilla. The glaze should have a smooth, pourable consistency—thick enough to coat but fluid enough to drizzle. Add extra milk or powdered sugar as needed to adjust.

Once bars are cool, drizzle the glaze over the top. Lift the bars out of the pan using the parchment paper overhang, then cut them into neat squares.