While they have origins in Moorish Spain, alfajores are especially popular in South America. They are simple shortbread sandwich cookies with a sweet filling of dulce de leche. Different doughs are used for the cookies depending on the country. Some use normal flour dough, while others add cornstarch or even cassava flour for a more delicate crumb.
1/4 c. plus 3 tbsp. butter
1/4 c. plus 3 tbsp. sugar
1 egg, beaten
3/4 c. plus 2 tbsp. flour
1 can condensed milk
Cream together butter and sugar; add egg and flour and mix well. Drop by scant teaspoonfuls onto cookie sheet. Pat with a floured finger into very thin little circles (quarter to half dollar size). Bake at 325 degrees for 10-12 minutes, until just starting to brown around edges.
Sandwich two cookies together with cooked condensed milk. To cook condensed milk, place entire, unopened can in a large saucepan, cover with water. Bring to boil and simmer about 2 hours. This turns it into caramel.