Step 1 - In large glass bowl, microwave the butter until it has melted. Add sugar and milk; whisk together well.
Step 2 - Microwave on high 3 minutes, stir and then microwave for another 2 minutes.
Step 3 - Mix well; scraping the sides of the bowl. Microwave on high for 3 more minutes, then stir and measure temp and then Microwave for another 2-3 minutes.
Step 4 - Remove from microwave and add chips. Stir vigorously until melted and smooth. Add the marshmallow creme and the Rodelle vanilla extract; mix well until you no longer see any white streaks. Pour into 9x9 pan that has foil in the bottom. Cool completely and cut into squares! Enjoy!