It has to do with added sulfur, used in order to preserve the bright orange color which we associate with the apricot. In this recipe, the pastry chefs ask specifically to use unsulfured apricots, which I found at Trader Joe's.
As you can see, they look vastly different from their sulfured counterparts. Not exactly an appealing color, might I add, but they are healthier for you, with no added sugar or preservatives. These are more tart than the sulfured ones, so if you're using the latter, add a little lemon to the filling mixture, as per David Lebovitz's instructions.
The chopped rosemary is added to the shortbread base; I used less than what BAKED recommended, as I still am a scaredy-cat when it comes to herbs and sweet foods. (Don't get me started on the chocolate basil dessert I had at Del Posto— a terrible way to end an otherwise amazing meal.) The apricot filling is tart, smooth and thick, and the crumb topping with chopped pecans (I used walnuts because I was too lazy to run downstairs to the deep freezer) provides textural and added buttery interest. The cookie got rave reviews from various tasters: "unusual," "addicting," and "delicious" were some of the adjectives.
Rosemary Apricot Bars
from Baked Explorations by Matt Lewis and Renato Poliafito
For the rosemary short dough
1¾ cups all-purpose flour
½ teaspoon salt
1 teaspoon fresh rosemary leaves, minced
12 tablespoons unsalted butter, cut into ½-inch cubes, at room temperature
½ cup confectioners' sugar, sifted
¾ teaspoon pure vanilla extract
For the apricot filling
2 cups dried California apricots (about 8 ounces)
½ cup granulated sugar
3 tablespoons honey
2 tablespoons brandy
For the crumb topping
½ cup all-purpose flour
½ cup firmly packed dark brown sugar
⅓ cup pecans, coarsely chopped
pinch of salt
3 tablespoons cold unsalted butter, cut into ½-inch cubes
Make the rosemary shortdough
Line a 9-inch square baking pan with foil.
In a medium bowl, whisk together the flour, salt and rosemary. In the bowl of a standing mixer fitted with the paddle attachment, beat the butter with the confectioners' sugar and vanilla at medium speed until fluffy, approximately 2 minutes. Turn the mixer to the lowest speed and stream in the flour mixture. Scrape the dough into the prepared pan, lightly flour your clean hands, and press it into an even layer. Place the pan in the refrigerator for at least 30 minutes.
Preheat the oven to 350ºF.
Bake the dough until it is golden 25 to 30 minutes, rotating the pan halfway through the baking time. Cool the pan on a wire rack, leaving the oven on.
Make the apricot filling
Place the apricots, sugar, honey, brandy, and salt in a medium saucepan with 1½ cups water and simmer over low heat for 40 to 50 minutes, or until the apricots are fork-tender and most of the liquid has evaporated or thickened. Remove the pan from the heat and stir the mixture to release the excess steam. Scrape the apricot mixture into a food processor and puree until smooth.
Make the crumb topping
In the bowl of a standing mixer fitted with the paddle attachment, combine the flour, brown sugar, pecans and salt. Mix on low speed for 15 seconds. Add the butter and mix until a sandy crumb begins to form, about 1 minute. (At this point, the crumb topping can be stored, covered, in the refrigerator until ready to use.)
Assemble the rosemary apricot bars
Spread the apricot filling over the shortbread, then sprinkle the crumb topping over the filling. Bake for 20 to 25 minutes, or until the crumb has browned. Let the pastry cool for at least 30 minutes in the pan, then lift it out using foil overhang and cut it into bars. The bars can be stored in refrigerator, tightly wrapped, for up to 3 days.