Hmm, I can't even remember seeing any baking courses advertised in German. Generally I'd say your best bet for finding teaching in English on any subject here is to find a course taught in German and ask whether the teacher minds doing some extra explanation in English. Some will, some won't -- it also depends on how the teaching is structured i.e. how much one-on-one interaction there is with the teacher.
The Cailler museum in Broc (canton Fribourg) offers courses in making chocolate confectionary.
http://www.cailler.ch/en/Atelier/Information.aspx
And it looks like the Kambly factory in Trubschachen (between Bern and Luzern) also offers some sort of confectionary courses.
http://kambly.ch/switzerland/kambly-...xperience.aspx
I don't have personal experience of either place. You'd have to call and ask what language they used, but since they maintain English versions of their websites I imagine they have some provision for catering for English-speaking visitors.
Good luck!
W.