8 tablespoons butter (1 stick) cut into chunks
7 ounces bittersweet chocolate, chopped
¾ cup flour
½ teaspoon baking powder
2 eggs, at room temperature
1 cup sugar
¼ teaspoon salt
2 teaspoons vanilla extract
2/3 cup chopped pecans, about 3 ounces
1/3 cup semisweet chocolate chips (optional)
½ cup dulce de leche (milk caramel)
Preheat oven to 325 degrees F. Prepare a piece of parchment paper 15” long. Fold it lengthwise to form a 9” wide piece. . With fold face down, place parchment into a 9” square pan allowing excess to hang over the edges of the pan. Spray with grease-and- flour spray.
Melt butter and chocolate in a double boiler set over a pan of barely simmering water. Stir occasionally until smooth and combined; set aside to cool. Whisk together flour and baking powder; set aside. In a separate bowl, beat eggs. Add sugar, salt and vanilla; whisk until combined. Add cooled chocolate mixture; whisk until incorporated. Add flour and stir to combine. Add chopped pecans and optional chocolate chips.
Spread half of brownie batter in prepared pan. Drizzle ¼ cup dulce de leche over batter. Drop remaining batter in large mounds over caramel layer. Drizzle additional ¼ cup dulce de leche over batter Using tip of a knife, swirl caramel and batter. Bake brownies for 35 to 40 minutes, until a toothpick inserted into center comes out with some moist crumbs attached. Cool brownies on wire rack for 1 ½ hours.
Holding the parchment edges hanging over the edge of the pan, lift out brownies. Peel away and discard paper. Cut brownies into 25 squares. Serve chilled or at room temperature. Yield 25 squares