PREHEAT OVEN TO 350 F DEGREES. LINE AN 8 OR 9-INCH SQUARE BAKING PAN WITH FOIL.
MAKE CREAM CHEESE LAYER: BEAT CREAM CHEESE AND BUTTER UNTIL SMOOTH, ADD SUGAR, MIX UNTIL WELL BLENDED THEN ADD IN THE EGG, FLOUR AND VANILLA, MIX WELL; SET ASIDE.
MAKE THE BROWNIES: IN A HEAVY SAUCEPAN, MELT BUTTER, ADD SUGAR, TAKE PAN OFF HEAT THEN WITH A WOODEN SPOON MIX BUTTER AND SUGAR WELL UNTIL IT’S COOL ENOUGH TO ADD THE EGGS AND VANILLA; MIX WELL. COMBINE FLOUR, COCOA, BAKING POWDER AND SALT IN A SEPARATE BOWL, STIR TO COMBINE. POUR SUGAR-EGG MIXTURE TO FLOUR MIXTURE, MIX UNTIL WELL COMBINED THEN POUR INTO PREPARED PAN.
ADD CREAM CHEESE MIXTURE ON TOP THEN THE DULCE DE LECHE; USING A TOOTHPICK OR POINT OF A KNIFE, CUT DULCE DE LECHE INTO THE CREAM CHEESE LAYER TO MAKE A MARBLE OR SWIRL EFFECT. BAKE BROWNIES FOR ABOUT 30 MINUTES OR UNTIL TOOTHPICK INSERTED COMES OUT CLEAN. COOL THEN CUT INTO SQUARES. ENJOY!