I have tweaked the directions for you below, so the steps are little more precise than my original copy.
Printable Copy
Grandma's Butter "Rum" Sauce
Makes approx. 1 1/2 cups Sauce
Ingredients: 1/2 cup brown Sugar
1/2 cup white Sugar
1 1/2 cups corn syrup, (light or dark)
1/2 tsp. salt
1/2 cup light cream or half and half
1/4 cup butter
1 tsp. vanilla
1 tsp. rum flavoring
Directions:
In a saucepan over medium heat add brown sugar, white sugar, corn syrup and salt. Blend till well mixed, and stir frequently till comes just to a boil.
Remove from heat.
Add butter, vanilla, and rum flavor when butter is mostly melted, add in the cream last.
Serve immediately, warm. or gently reheat .
Store in refridgerator up to 3 months.