• Preheat oven to 350°F. Prepare a 9 x 13-inch baking pan by lining it with a piece of parchment that slightly overhangs the edges. This will allow you to lift the entire bar out of the pan and easily slice them.
• In a medium bowl, whisk together the 3 cups flour, 1 1/2 teaspoons baking powder and 1/2 teaspoon salt.
• In a large mixing bowl, cream the 1/2 cup butter and 1/2 cup shortening on high until smooth and well combined. Add the 1 3/4 cups sugar, and completely combine. Be sure to scrape down the sides and bottom of the bowl.
• Add the 3 eggs and 1 teaspoon vanilla and mix well. Add the flour mixture and thoroughly combine. Set aside 1 1/4 cups of the dough for the topping.
• Press the remaining dough into the prepared pan. I find it easiest to place dollops of dough around the parchment and then spread with an offset spatula. Bake for 12 minutes. The edges will be lightly golden, and the middle will appear to be underbaked, but not to worry, you're going to bake them again.

Cranberry Filling

• In a large bowl, combine the 2 1/2 cups cranberries, 1/3 cup granulated sugar, 1 tablespoon cornstarch, 1 tablespoon orange zest, 1 tablespoon orange juice, and 1 teaspoon vanilla. Mix well and evenly distribute the filling over the baked crust.
• Place small dollops of the remaining dough over the cranberries, leaving some space in between so you can see some of the filling on top of the bars.
• Bake for about 35-40 minutes until the crust is golden brown. If browning too quickly, loosely place a piece of tin foil over the pan and bake until set. Set pan on a baking rack to cool completely before before glazing.

Orange Glaze

• In a small bowl, mix together the 1 cup powdered sugar. Add the zest and juice of the one orange. If needed, add additional orange juice 1 teaspoon at a time until glaze is of a consistency where it can be drizzled.
• Using a spoon, evenly distribute the glaze over the top of the bars. Lift bars out of the pan by the parchment and slice.