Young hosts are turning their apartments into makeshift coffeehouses, and documenting the process on social media. Are they social events or side hustles?

The week before Morning Jays opens, Nate Crawford and Justen Lambert kick into overdrive.

To start, they draft a menu, with three sweet pastries from Mr. Crawford and three savory dishes from Mr. Lambert. Forty-eight hours out, they visit multiple grocery stores — their selections often feature in-season ingredients — and dive into prep, chopping, tasting and tweaking as they go.

Come Saturday, they’re up at dawn, jockeying for oven space, brewing coffee, plating and decorating, while setting out to-go cups and totes stamped with the blue Morning Jays logo. Then they slip on branded T-shirts and await their guests.

These are not paying customers, however, they’re friends and family. Because Morning Jays is not a real cafe. It’s an apartment in Des Plaines, Ill., made to look and feel like