The joke at the end was already too obvious. One thing I didn't get (and this just be my inexperience with different apartment layouts) was where exactly Rich's kettle-corn-popping "garage" would be with an apartment hallway like that.

Some apartments have garages available. Maybe he does it there. Was he working on it when Joel showed up? I thought he said he was baking.

I know some do, but I've never seen them with such narrow, interior hallways like that. I don't know, they just look different around here.

Yeah, he was baking muffin tops but I imagine that was just in his kitchen

It's probably his storage area where he keeps and dismembers his victims after having killed them with his kettle corn paddle.

I assumed it was winter break since A) it's winter, and B) they started a new semester.

I thought the "Happy New Year" as one of the first things said helped make that clear as well.

Also, Shirley being 8 weeks along since Halloween puts it at the new year.

ding! i don't know how anyone would think it was spring break. the show always syncs up with the school year.

That and the sweater joke should get this show an Emmy...

Well, I'll explain how: read the original poster's plot summary.