Butterscotch Brownies are kind of just one of the original names for Blondies.  The sugar, butter, and vanilla combined to make the flavour for the treats is like butterscotch and an alternative to the chocolate brownie.  A butterscotch Brownie could also have butterscotch baking chips in it, but the sale of these is much later than the original recipes for Butterscotch Brownies.  For my cookies I melted down butterscotch chips for the batter as well as added chips in whole.  A homemade butterscotch could also be added to the batter for a more traditional style.

Butterscotch candy became popular in the mid 19th century.  Some early recipes called for butterscotch to be mixed with flower and baking powder.  This is like an early version of the butterscotch brownie.