There is no such thing as EASA approved. You could write it on a piece of toilet paper as long as it mentioned all the required details. Format does not matter.
I personally don't use a European logbook - I started another one a long time ago and no CAA has ever objected.
That said: You can start a new logbook and continue from there, or rewrite the old hours in the new logbook and just add a photocopy of the necessary stamps and signatures in the back. Pretty common.