The combination of chocolate and ducle de leche is simply heaven! Dulce de leche is made from boiling milk and results from an intense and thick caramelization of it. You can make your own or buy it, ready made from the grocery store. This was developed from my Double Chocolate Fudge Brownie Bars Recipe, published in my Baking 9-1-1 Book by Simon and Schuster in 2003. If you want more dense fudge brownies, increase the chocolate squares to 6 ounces, and decrease the sugar to 1 cup. Some fudge brownie purists even omit the baking powder.
COOKIE RECIPE HELP

INGREDIENTS
1 cup unbleached all-purpose flour (spoon flour into measuring cup and level to top)
1/4 cup unsweetened Dutch-process cocoa powder
1/2 teaspoons baking powder
1/4 teaspoon salt

3 ounces bittersweet or semisweet chocolate, finely chopped (any cacao percentage will work)
1/2 cup (1 stick) salted or unsalted butter

3 large eggs
2 teaspoons vanilla extract

1 1/2 cups sugar
1/2 cup chopped walnuts, optional

1 cup thick Caramel or Dulce de Leche or Crockpot Dulce de Leche or purchase ready-made

INSTRUCTIONS
1. Position a rack in the center of the oven and preheat to 350 degrees. Grease an 8- x 8- inch baking pan. Set aside.

2. In a medium bowl, sift together the measured flour, cocoa powder, baking powder and salt. Set aside.

3. Put the chopped chocolate in a small bowl. Warm the butter in a saucepan until just melted and remove from the heat. Pour the butter over the chocolate. Swirl the pan so the hot butter warms all the chocolate and covers it. Let the mixture sit 2 minutes. Stir to melt the chocolate. Let cool until slightly warm.

4. With a fork, beat the eggs and vanilla together in a medium bowl until just combined. Stir in the sugar with a rubber spatula. Pour in the cooled butter-chocolate mixture and mix until smooth. Do NOT whip. In 2 additions, with a rubber spatula, fold in the flour mixture until almost combined, and then the walnuts until all are fully combined. The batter will be thick and look like fudge.

5. Scrape half of the brownie batter into the prepared pan. Drop one-third of the Dulce de Leche, in dollops (spoonfuls), evenly spaced, over the brownie batter, taking care not to get any near the pan sides – leave about a 1/2-inch – otherwise the sugar from it will burn during baking. Then drag the tip of a paring knife through to swirl it slightly taking care not the tear the foil liner. As best you can, carefully spread the remaining brownie batter over. Then drop dollops (spoonfuls) of the remaining Dulce de Leche over the top of the brownie batter. With the tip of a paring knife, swirl the Dulce de Leche slightly.Tap the pan lightly on the countertop a few times to remove excess air bubbles.

6. Bake for exactly 40 minutes. This recipe will puff slightly in the oven, then fall and crack; it's normal. The brownies will seem underdone in the middle but will harden as they cool. DO NOT OVERBAKE. Cool in the pan on a wire cake rack before cutting into squares.

STORAGE
Store well-covered at room temperature for 3 to 5 days. Freezes well for up to 3 months.