Burnt Toast

Cook along with Jesse Szewczyk to make these crunchy, perfectly spiced, and understated shortbread cookies that are as delicious dunked into hot coffee as they are eaten all on their own.RecipeMakes 24 bars Shortbread Base1 2/3 cups (214g) all-purpose flour1/3 cup (67g) granulated sugar1/2 teaspoon kosher salt12 tablespoons (1 1/2 sticks/170g) unsalted butter, melted1 large egg yolk1 teaspoon vanilla extractSalted Speculoos Caramel3/4 cup (175 grams) packed light brown sugar4 tablespoons (1/2 stick/57g) unsalted butter1/4 cup (59 ml) light corn syrup1 14-ounce can (414 ml) sweetened condensed milk1/3 cup (90 grams) speculoos cookie butter (see Note)1 teaspoon vanilla extract1 teaspoon kosher saltTopping1/2 cup (about 3 ounces/85 grams) semisweet chocolate chips1/2 cup (about 3 ounces/85 grams) white chocolate chips4 tablespoons (59 ml) whole milk, divided2 tablespoons (36 grams) speculoos cookie butter, dividedFlaky sea salt, for sprinklingMake the shortbread base: Heat the oven 325°F. Grease an 8- by 8-inch