These raspberry crumb bars are, in a word, perfection. I may or may not have eaten 3 the day I made them, but that's irrelevant. The recipe is long and tedious, but don't let that discourage you, the payoff is well worth it - the shortbread is so buttery and crumbly I didn't even have to strategically place the crumbs for my photos. If that's not quality shortbread I don't know what is.
Raspberry Crumb Bars
from Flour: Spectacular Recipes from Boston's Flour Bakery + Cafe by Joanne Chang
1 1/2 cups (3 sticks/342 grams) unsalted butter
1/2 cup (100 grams) granulated sugar
3 tbsp confectioners' sugar
2 egg yolks
1 tsp vanilla extract
1 1/4 cups (175 grams) unbleached all-purpose flour
1 1/2 cups (180 grams) cake flour
3/4 tsp baking powder
3/4 tsp kosher salt
1 1/2 cups (510 grams) raspberry jam (with seeds)
1/4 cup (35 grams) confectioners' sugar (optional)
- To make the shortbread: Using a stand mixer fitted with the paddle attachment, cream together the butter, granulated sugar, and confectioners' sugar on medium speed for about 5 minutes, or until the mixture is light and fluffy. Stop the mixer a few times to scrape down the bowl and paddle. Beat in the egg yolks and vanilla on medium speed for 2-3 minutes, or until thoroughly combined. Scrape down the bowl and paddle again.
- In a medium bowl, sift or whisk together the all-purpose flour, cake flour, baking powder, and salt. On low speed, gradually add the flour mixture to the butter-sugar mixture and then mix for about 15 seconds, or until the flour mixture is totally incorporated and the dough is evenly mixed. Scrape down the bowl again and make sure all of the flour mixture is thoroughly incorporated.
- Scrape the dough onto a sheet of plastic wrap. Remove one-fourth of the dough to a separate sheet of plastic wrap. Wrap the remaining three-fourths of the dough entirely in the plastic wrap, pressing down to form a disk about 8 inches in diameter and 1 inch thick. Refrigerate the dough disk for about 30 minutes, or until the dough has firmed up but is still somewhat pliable. Pat the reserved one-fourth of the dough into a small disk, wrap in the plastic wrap, and place in the freezer for at least 2 hours, or until hard. (At this point, the smaller dough portion can be stored in the freezer for up to 1 month. The larger dough disk can be stored in the refrigerator for up to 5 days or in the freezer for up to 1 month. If the larger dough disk is frozen, thaw it overnight in the refrigerator, then let it sit at room temperature for about 20 minutes before using.)
- Position a rack in the center of the oven and preheat the oven to 350 degrees F.
- Lightly flour the 8-inch dough disk and two large sheets of parchment paper. Place the dough between the sheets of parchment, and roll it out into a rectangle about 13 by 9 inches and 1/4 to 1/3-inch thick. Carefully peel off the top sheet of parchment. Trim the edges so the rectangle has fairly neat sides. Transfer the bottom sheet of parchment with the dough to a baking sheet. Trim the parchment paper so that it fits the baking sheet.
- Bake for about 20 minutes, or until the shortbread is light brown. Remove the shortbread from the oven (leaving the oven set at 350 degrees F), let cool for 10-15 minutes, and then spoon the raspberry jam on top of the still-warm shortbread. Spread it in an even layer with the spoon or with a rubber spatula, covering the surface. The heat of the shortbread should soften the jam enough to make it spreadable.
- Remove the smaller dough disk from the freezer and, using the large holes on a box grater, grate it into large flakes and evenly sprinkle over the jam. (I found it easier to grate the dough flakes right over the jam because otherwise they softened and clumped together, making them impossible to "sprinkle.")
- Return the baking sheet to the oven and bake for another 20-25 minutes, or until the top is lightly browned. Let cool completely on the baking sheet on a wire rack.
- When cooled, sift the confectioners' sugar evenly over the top. Trim the edges again, then cut into bars.
The bars can be stored in an airtight container at room temperature for up to 5 days.