1. Preheat the oven to 350°F and line an 8 × 8-inch baking pan with parchment paper.
2. In the bowl of a stand mixer fitted with the paddle attachment, cream the butter, granulated sugar, and brown sugar until light and fluffy, about 3 minutes. Scrape down the sides of the bowl.
3. Add the egg and vanilla and mix until combined. Scrape down the sides of the bowl as needed.
4. In a separate bowl, whisk together the flour, baking powder, cinnamon, and salt.
5. Add the dry ingredients to the butter mixture and mix just until the dough starts to pull away from the sides of the bowl. Do not overmix.
6. Set aside approximately 2 loosely packed cups of dough for the crumble topping.
7. Press the remaining dough evenly into the prepared baking pan, pressing it into the corners with your hands or the flat side of a measuring cup.
8. Bake for 15 minutes, until the edges are slightly golden and the center is just set. Do not overbake.
9. Remove the pan from the oven and let the crust cool slightly while preparing the filling.
10. In a large bowl, combine the cranberries, sugar, cornstarch, orange zest, orange juice, and vanilla. Pour the cranberry mixture over the prebaked crust.
11. Break the reserved dough into smaller, flat pieces and arrange them over the cranberry filling, leaving spaces for the cranberries to show through.
12. Bake for about 45 minutes. Cover the pan with aluminum foil for the last 10–15 minutes to prevent the crumble topping from becoming too dark.
13. Remove the bars from the oven and cool completely in the pan on a wire rack before adding the glaze.

Vanilla Glaze

1. Whisk together the powdered sugar, milk or heavy cream, and vanilla until smooth. The glaze should be thin enough to run off a fork but not transparent. Add more milk if too thick or more powdered sugar if too thin.
2. Drizzle the glaze over the completely cooled bars.
3. Slice into squares and serve.