Late Night Donut Run

I spent the weekend visiting a friend who lives in Maryland. She lives in a relatively uninteresting town, but they have a late night donut shop. It's only open from 10pm to 2am, and has been operating for almost a century. It's very strange to get donuts late at night, and the shop is not near any bars like you might think. It's located in a neighborhood and it's almost impossible to find unless you find this sign for donut crossing!