@AlbaWaterhouse - At my Sims bakery....she was able to sell single items. It was a bit time consuming because she had to pick up a serving (& of course trying to make her not eat it). & then I could click it and set it for sale....or I put it in the warming rack thingy. I too, liked the realism of serving a single helping versus selling bulk. My bakery has now expanded into basically everything....as my Sim sells everything from baked goods, to turkey dinners, to ambrosia.
Your thread has inspired me to have my Sims open their bakery....so thank you for the inspiration. I'm playing a legacy challenge and my Gen 2 heir opened up a bakery. I'm in Gen 5 now, & I dont think it's been open since. Will definitely be doing that next time I'm in game :)