Directions

Cream the sugar and butter in a large bowl or cake mixer until light and fluffy. Add the egg yolks, lemon zest, lemon juice, and caraway seeds and mix until all the ingredients are well combined.

Sift the flour and baking soda into the butter mixture and stir until just combined. The dough will be quite soft.

Place the dough on a large piece of plastic wrap and form into a 1 1/2-inch-diameter log. Twist the ends of the plastic securely, then place in the freezer until hard.

Preheat oven to 375 degrees F. line a baking sheet with parchment paper. Unwrap the dough and cut into 1/4-inch slices. Place the cookies on the prepared baking sheet about 2 inches apart. Bake until just golden, about 12 minutes.

Allow the cookies to cool for 2 minutes on baking sheet then slide them onto a wire rack to cool completely. Store in an airtight container until ready to serve.

To make the dulce de leche: Preheat the oven to 425 degrees F. Pour the condensed milk into an oven proof pie dish, add the vanilla and nutmeg, and mix well. Cover with foil, place the dish in a hot water bath, and bake until the mixture thickens and begins to caramelize, about 2 1/2 hours. Remove the foil and let cool. Refrigerate in a glass jar until ready to serve.

To assemble the cookies into sandwiches: Use a spatula to spread about 2 tsp of dulce de leche onto the flat (bottom) side of a cookie, then place another cookie on top.