Which company is credited with inventing the spelling "donut" in the 1920s?

The Display Doughnut Machine Corporation is credited with popularizing the spelling “donut” in the 1920s.

The company was associated with automated doughnut-making equipment and shortened “doughnut” for marketing purposes. The simplified form was intended to be easier for non-English-speaking customers and prospective buyers of the machines to pronounce. This attribution comes through food historian John T. Edge’s account of the company’s promotion.

The company did not create the first printed use of “donut.” That spelling appears earlier, notably in George W. Peck’s 1900 book Peck’s Bad Boy and His Pa. The 1920s machine-company story instead concerns the spelling’s promotion and commercial visibility.

“Doughnut” remains the traditional and internationally common form, while “donut” became especially prominent in American usage. Dunkin’ Donuts helped make the shorter spelling familiar after its 1950 naming, but it was not the company credited with originating the 1920s abbreviation. The Doughnut Corporation of America was a later corporate development, not the answer to this question.