Step 1

In large glass bowl, microwave the butter until it has melted. Add the sugar and milk; whisk together well.

Step 2

Microwave on high for 3 minutes, then stir, then microwave on high 2 minutes more.

Step 3

Mix well; scraping the sides of the bowl. Microwave on high for 3 more minutes, then stir and measure temp. You're looking for it to reach 234 degrees F. Microwave for 1 to 2 more minutes until 234 degrees is reached.

Step 4

Remove from the microwave and add the chocolate chips. Stir vigorously until melted and smooth. Add the marshmallow creme and the vanilla extract; mix well until you no longer see any white streaks. Pour into a greased 9-inch square pan, or 13x9-inch baking pan (depending on how thick you would like your fudge)- I used 9x9-inch for the photo.

Step 5

Cool completely at room temperature. Cut into squares.