My Tante Christel kept packages of sweet tart shells stocked in her kitchen when I was a kid. Tucked in the cupboard for safe keeping, she would grab a few to top with cream and fresh fruit for Kaffee und Kuchen in the late afternoon. That is, she'd grab them if she could find any. I had a nasty habit of pilfering anything vaguely sweet and leaving very little evidence of their existence behind.
The texture of the pastries, part crispy shortbread/part tender lady finger, has haunted me more than any shame at my delinquency in stealing the things. With a random knob of cream cheese floating freely in the fridge, I took the opportunity of harnessing my acute taste memory of all experiences sweet to reproduce that singular pastry but in cookie form. And with a can of sweetened condensed milk rumbling away in a water bath, well on its way to becoming dulce de leche, I'd have a perfect filling for my culinary flash back.
By the way, if my Tante Christel is reading this: you weren't going crazy. You did, in fact, repeatedly stock up on tart shells and I made it a point to eat every last one of them. The good news is that I can now be counted on to make as many as you need next time I'm in Germany, assuming I can keep from eating them all.
DULCE DE LECHE SANDWICH COOKIES
(makes 18 sandwich cookies)
For the dulce de leche
1 can sweetened condensed milk
1/2 teaspoon kosher salt
Fill a deep stockpot with water and bring to a tame boil. Take the label from the can and carefully transfer the can to the water bath, making sure the can is completely submerged. "Cook" the can for 2 1/2 hours, making sure that the can is always completely covered with water.
Carefully remove the can from the water and allow to cool until you can safely handle the can. Open the can and stir in the salt. Transfer the dulce de leche to a pastry bag fitted with a flat ribbon tip.
For the cookies
1 1/2 cups all purpose flour
1 1/2 cups cornstarch
1 teaspoon baking powder
1 teaspoon salt
1/2 teaspoon lemon zest
3/4 cup granulated sugar
6 tablespoons softened, unsalted butter
6 tablespoons room temperature cream cheese
4 egg yolks
1 tablespoon sweetened condensed milk
1 tablespoon vanilla
Preheat oven to 350ºF. Line 2 sheet pans with parchment. Set aside. Combine the flour, cornstarch, baking powder, salt and lemon zest in a large bowl and whisk for 30 seconds to distributed the ingredients. Set aside.
In the bowl of a stand mixer fitted with the paddle attachment, combine the butter and sugar. Mix until smooth. Add the cream cheese and mix on high until smooth. Add the egg yolks, one at a time, mixing briefly between each addition. Scrape down the bottom and sides of the bowl and add the sweetened condensed milk and vanilla Mix to combine.
Add the dry ingredients all at once and mix on low until the mixture just comes together.
Transfer the dough to a large piece of plastic wrap. Gently knead the dough until it's smooth and no clumps of flour remain. Cover completely in the plastic wrap and refrigerate for 20 minutes.
Roll the dough out onto a lightly floured work surface to between 1/8" and 1/4" thick. Cut the dough into 1" x 4" rectangles and transfer to the prepared sheet pans. Space the cookies about 1/2" apart and place the cookie lined sheet pan in the freezer for 5 minutes.
Bake for 12-15 minutes or until the cookies just start to brown on the edges. Allow to cool completely.
Pipe the underside of one cookie with the dulce de leche and top with another. The cookies keep for up to 3-4 days when kept in an airtight container. The flavor tends to develop even more after one day.