Step 1

Place butter in a saucepan and melt over medium-low heat.

Step 2

Add the brown sugar and milk and turn heat to medium. Stir constantly until the mixture boils. Boil for 2 minutes.

Step 3

Remove from heat and stir in vanilla and salt. (Once it cools a bit, you can add more salt to taste.)

Step 4

Pour into jar. Let cool slightly before using. Cover. Store in refrigerator if not using the day it's made.

Step 5

If mixture separates as it cools, just stir it up or shake it.

Step 6

If it becomes to thick to pour after chilling, you can heat it in the microwave for a few seconds and stir.