LINE AN 8 OR 9 INCH SQUARE PAN WITH ALUMINUM FOIL OR PARCHMENT PAPER. COAT WITH NONSTICK SPRAY. SET ASIDE.
IN A 3 QUART HEAVY SAUCEPAN OVER HIGH HEAT, COMBINE SUGAR, BUTTER, AND EVAPORATED MILK. USE A WOODEN SPOON TO STIR SLOWLY UNTIL BUTTER MELTS, SCRAPING SIDES OF PAN TO GET ALL THE SUGAR CRYSTALS.
BRING TO A FULL ROLLING BOIL, STIRRING CONSTANTLY WITH A LONG WOODEN SPOON. ONCE IT STARTS BOILING, SET A TIMER FOR 5 MINUTES AND TURN THE HEAT DOWN TO MEDIUM SO THAT YOU DON’T BURN YOUR FINGERS OFF–IT SHOULD BE BOILING THE FULL 5 MINUTES. STIR CONSTANTLY.
WHEN THE TIMER GOES OFF, REMOVE FROM HEAT AND ADD CHOCOLATE CHIPS. STIR UNTIL ALL CHIPS ARE MELTED AND MIXTURE IS SMOOTH. ADD MARSHMALLOW CREME AND BEAT WITH A WOODEN SPOON UNTIL WELL BLENDED. ADD VANILLA AND MIX WELL. IMMEDIATELY POUR INTO THE PREPARED PAN.
LET COOL TO ROOM TEMPERATURE. (GOOD LUCK WITH THAT.)
SLICE AND SERVE! STORE ON THE COUNTER COVERED.
