According to “The Ultimate Brownie Book,” blondies came before brownies. Brownies were a variation. I always thought it was the other way around. The first known brownie recipe from Fannie Farmer’s 1896 “Boston Cooking School Cookbook,” doesn’t include chocolate but has molasses and was “browned” giving it its name. The 1918 edition which is online has a listing for brownies which includes chocolate in the cookies section, but also has a molasses version in Cakes. I’ll have to check the 1896 reprint next time I see it in a bookstore to see if both versions existed then. A search on blondies in the 1918 cookbook doesn’t turn up anything, but there is likely something similar under a different name.