Preheat oven to 350℉ and prepare an 8 x 8″ baking pan with parchment paper. Parchment paper is much easier to work with, makes cleanup easier, and overhanging the sides a bit helps lift the finished brownies out.
Grab a medium mixing bowl and combine flour, cocoa powder, salt, and baking powder. Use a whisk to thoroughly mix.
In a separate large bowl, use a handheld or stand mixer to mix the stick of melted butter with sugar. Mix in the eggs and vanilla extract until well combined.
Add the dry ingredients from Step #2 to the bowl of wet ingredients. Mix until just combined.
Grab the prepared baking pan and add in half of the brownie batter. Then drop in half of the dulce de leche over the batter, and use a knife to swirl or mix it into the batter.
Sprinkle the chocolate chips over the top, then add the remaining half of the brownie batter over the top.
Next, add in the other half of dulce de leche over the batter, and once again use a knife to swirl or mix it into the batter.
Bake it @ 25-30 minutes or until a toothpick entered into the center comes out clean.
Carefully remove the brownie pan from the oven and allow it to cool for 5-10 minutes. Lift the brownies out using the parchment paper overhang, then cut into squares. Enjoy!