Caramel Sauce with Condensed Milk

I was out of heavy cream and wanted to make a caramel sauce. 
So I used a can of condensed milk to make this sauce.

1 cup brown sugar
1/2 cup maple syrup
1/2 cup butter
Pinch of salt
1 can condensed milk

Mix Sugar, Maple Syrup, Butter and pinch of salt. Bring to a boil. 
Simmer for two or three minutes. Add  Condensed milk, stirring until
well mixed.  Simmer for 60 seconds.   Remove from heat, add vanilla. 
Pour into bowl or jar with lid and refrigerate.