Ingredients
Equipment
Method
- Preheat the oven to 350 F. Line a 9x13 inch pan with parchment paper, leaving a 2 inch overhang on the two long sides so you can lift the slab out later.
- Whisk the flour, baking powder, ground ginger and salt together in a small bowl and set aside.
- In a large bowl, beat the melted butter and packed light brown sugar with a hand mixer on medium speed for about 1 minute, until smooth and glossy with no sandy pockets.
- Beat in the eggs one at a time, then the vanilla, 2 teaspoons of the orange zest and the orange extract if using. Mix for 30 seconds more, until the batter looks silky and slightly lightened.
- Add the flour mixture and fold with a spatula only until the last streaks of flour disappear. Stop there. Overmixing develops gluten and turns the bar cakey instead of dense and chewy.
- Fold in the 3/4 cup white chocolate chips and 3/4 cup dried cranberries. The batter will be very thick, more like cookie dough than cake batter.
- Scrape the batter into the prepared pan and press it into an even layer with the spatula or lightly dampened fingertips, pushing it all the way into the corners.
- Bake for 18 to 22 minutes, until the top is golden, the edges have just pulled from the sides and the center still looks barely set. A tester in the middle should come out with moist crumbs clinging to it, not clean. This slight underbake is what gives the bars their chew.
- Cool the slab completely in the pan on a wire rack, at least 1 hour. If the base is even faintly warm the cream cheese icing will slump and melt.
- For the icing, beat the room temperature cream cheese and the 4 tablespoons of butter on medium speed for 2 minutes, until completely smooth with no lumps.
- Add the sifted powdered sugar in two additions, beating on low then medium until creamy. Beat in the vanilla and the remaining 1 teaspoon of orange zest. The icing should be thick enough to hold a soft peak but spreadable.
- Spread the icing over the cooled slab in an even layer with an offset spatula, taking it right to the edges.
- Scatter the chopped dried cranberries over the icing.
- Melt the 1/2 cup white chocolate in a microwave-safe bowl in 20 second bursts, stirring between each, until just fluid. Transfer to a small zip bag, snip a tiny corner and drizzle thin diagonal lines across the slab in one direction, then the other, to make a crosshatch.
- Refrigerate the slab uncovered for 30 to 60 minutes, until the icing is firm to a light touch.
- Lift the slab out by the parchment onto a cutting board. Trim the edges if you like, then cut into 12 squares using a long knife warmed under hot water and wiped completely dry. Slice each square corner to corner to make 24 triangles, wiping and rewarming the blade between cuts.
- Serve chilled or at cool room temperature.
