A variation made with brown sugar and vanilla rather than chocolate in the batter is called a blond brownie or blondie.

[1] In 1893, Palmer asked a pastry chef for a dessert suitable for ladies attending the Chicago World's Columbian Exposition.

[2] The first-known printed use of the word brownie to describe a dessert appeared in the 1896 version of the Boston Cooking-School Cook Book by Fannie Farmer, in reference to molasses cakes baked individually in tin molds.

The earliest-known published recipes for a modern-style chocolate brownie appeared in Home Cookery (1904, Laconia, New Hampshire), the Service Club Cook Book (1904, Chicago, Illinois), The Boston Globe (April 2, 1905 p. 34),[2] and the 1906 edition of Fannie Farmer's cookbook.

[12] In 2021, the food science journalist and home cookery YouTuber Adam Ragusea conducted a series of experiments to discover why modern brownies tend to form a desirably glossy "skin" on their upper crust.

In a video reporting his findings, Ragusea asserted that the "skin" was the result of making a batter of high viscosity, with low levels of moisture and sugar well-dissolved into the mixture.