Egg yolks bind the dough while keeping the overall water content to a minimum, so the cookies are easy to roll yet tender after baking.
Vanilla bean keeps the dough flavorful but dry, so it’s easy to handle.
A food processor minimizes aeration of the dough while keeping it nice and cold, so the dough doesn’t need to be chilled and the cookies won’t puff or warp with pockets of air.
Flecked with vanilla seeds throughout the dough, alfajores are the perfect excuse to whip up a batch of vanilla bean cajeta—a goat’s-milk variation on dulce de leche. The combination of gooey toffee sauce and buttery shortbread can’t be beat, but it can be improved upon. My recipe replaces traditional cornstarch with tapioca starch, keeping the alfajores tender and light, with a clean finish that truly melts away. Pair them with a mug of strong black coffee, or a nip of Rainwater Madeira.
1 vanilla bean, preferably Mexican
4 ounces all-purpose flour (3/4 cup plus 1 tablespoon; 115g)
3 ounces tapioca starch (3/4 cup; 85g)
2 ounces powdered sugar (1/2 cup; 55g), plus more for dusting
1/4 teaspoon (1g) Diamond Crystal kosher salt
1/4 teaspoon (1g) baking powder
4 ounces cold unsalted butter (1 stick; 115g), cut into 1/4-inch pieces
2 large egg yolks, cold
1 recipe Cajeta Casera (see note)
