Bring a Medium Sauce Pan to Medium Low Heat. Whisk together Milk & Sugar. Being to a Low Simmer, and Whisk often. Continue to Simmer, until the Milk has Reduced by about Half. This will take 30 Minutes or more. Turn off Heat, & add Butter & Vanilla. Stir Well & allow to Cool.

Use Immediately or Pour into a Mason Jar and Refrigerate for up to a Week. Makes around 1 1/4 to 1 1/2 Cups.