She offers it as a reward in the course of the game. During the ending credits a cake is shown at the end IIRC.
In Portal 2 GLaDOS says something in fast motion to "explain" how to solve the test. What she is really doing is quoting a line from Moby Dick: "...and methodically knocking people's hats off--then I account it high time to get to sea as soon as I can." Now you really can remember what she said in slow motion like she told you to!
GLaDOS Genetic Lifeform and Disk Operating System I'd say her real name but it would ruin the surprise.
In Portal 1 people say that Caroline hasn't had her mind put in but she kills everyone in the facility (Aperture Laboratories) so it is not that. So can you figure it out?
portal (портал) в интернет!
I would say it was an "orange portal", but maybe that's just me.
There is no translation, so you can just say 'cake.'
Portaal.
"Tobira."
Chell is the protagonist of the game. It doesn't say for sure, but some speculate that when Aperture Science held it's first 'bring your daughter to work day' the AI they had constructed, GLaDOS, took over the facility and used the daughters as test subjects. So Chell could probably be a daughter of one of Aperture Science's employees.
You can say it simply like that, just make it more polite. Maybe something like, "I intended to make the cake, but my skills were not that good" or "I really wanted to make the cake, but didn't think I could do it right and then have to serve everyone a bad cake" or something like that.
In Flanders, we call cake cake. The pronounciation stays the same.
You would say cake in the Abaluhya language as keki.