On March 23, 1965 astronaut John Young launched to Earth’s orbit aboard the Gemini 3. With him were crewmate Gus Grissom and a two-day-old corn beef sandwich, smuggled without permission on the spacecraft....
The two might have had some laughs, but when they got back home no one was laughing.
Grissom put the sandwich away after a bite or two, but even that was enough to litter the cabin in a myriad of floating breadcrumbs. ...
However, NASA et al are trying to solve the bread problem.
more at Gizmodo
To bake the space bread, most likely a low-energy convection oven will be used to bake a special dough that produces a crumb-free bread. The challenge is to make a crumb-free bread tasty too since this property often means baking tough and chewy bread. According to Bake In Space, the food produced will be an adapted type of weekend German bread rolls. The hope is the fresh bread will not only offer sustenance but psychological comfort too.
and here is how to make a peanut butter sandwich in space