Dulce De Leche

1. Place the can of condensed milk (with the label removed) on its side in a medium deep-bottom sauce pan.
2. Fill the pan with enough water to cover the can of condensed milk. Water should reach at least 2 inches above the can.
3. Place pan over medium high heat to bring the water to a boil and then lower heat to medium low to simmer.
4. Cook condensed milk for 3-4 hours refilling the pan with water as needed. I like to rotate and flip the can of condensed milk onto the opposite side with kitchen thongs about every 30-40 minutes.
5. For a lighter colored dulce de leche, use kitchen thongs to remove can from water after 3 hours. For a darker colored dulce de leche, remove can from water after 4 hours.
6. Allow can to cool to room temperature before opening and spooning out dulce de leche into an airtight container. 

Alfajores (Dulce De Leche Cookies) 

1. In a medium mixing bowl, add the flour, cornstarch, baking powder and salt. Whisk ingredients together to combine.
2. In the bowl of a stand mixer fitted with paddle attachment or in a large mixing bowl with a hand-held mixer, add the butter and sugar. Cream ingredients together at medium high speed until mixture appears pale yellow with a fluffy consistency, about 2-3 minutes.
3. Beat in the vanilla extract into creamed butter mixture followed by the egg yolks and milk. Use a spatula to scrape the sides and base of the mixing bowl.
4. Reduce mixture speed to low. Add all of the dry ingredients into wet batter and mix just until cookie dough forms, about 1 minute.
5. Stop mixer and transfer cookie dough to a clean work surface.
6. Shape cookie dough into a slightly flattened disk shape and wrap in plastic/cling wrap. Refrigerate cookie dough for 2-3 hours or until firm. 
7. Line two large baking pans with parchment paper.
8. Transfer chilled dough to a lightly floured work surface. Lightly flour the top of dough and roll into a large circle that is between 1/8-1/4 inch thick.
9. Use a 2-inch cookie cutter to cut out as many cookie dough circles as you can.
10. Transfer cookie dough circles to parchment lined baking sheets taking care to place them at least 1/2 inch apart.
11. Re-roll dough scraps and repeat the process of cutting out more cookie dough circles for a total of 36 to 40 cookies.
12. Preheat the oven to 350F(177C). Place baking sheets with cookie dough cutouts in the fridge to chill for 30 minutes. This step is optional but will allow butter in dough to firm back up and help prevent overspreading of cookies as it bakes.
13. Bake cookies for 9-10 minutes rotating the pan halfway through bake time. I do not recommend baking cookies beyond the 10 minute mark as doing so may result in dry, crumbly cookies. 
14. Allow cookies to cool on baking sheets for 3-4 minutes before transferring to a cooling rack to cool completely to room temperature.
15. Spoon about 1/2 tablespoon of dulce de leche into the center of the bottom of one cookie before topping with another cookie. Gently press cookies together to form a sandwich. Repeat with remaining cookies for a total of 18 to 20 cookie sandwiches.
16. Dust the tops of cookie sandwiches with powdered sugar before serving.