My ex and I have been living separate for a year now we have spent very little time together, this weekend he is helping me re arrange furniture and we are having pizza together we are getting together the next night and making our favorite dish together. What does this mean?

Who set up the "making our favorite dish" night?

If he did, ask him where his intentions are. You should not feel lead on or confused about what you are (friends or dating again).

It has been a full year, and if you are over him (as BF/GF) and are OK with just being friends, then this will be easy. But if he wants to be friends and you have feelings, I would strongly suggest not putting yourself in this situation.

I agree with sarper11.
Either he still has feelings for you or you with him... depending on who set this "rearranging" thing up.
Now if you got over him don't put yourself in that situation ask him what his intentions are and if just staying as friends then its OK but if he wants more than that forget it.
You two might end up hurt again so just don't do it!

It means you still have feelings and are letting him back in your life.

Since you want to know what his intentions are, ask now and avoid any drama, confusion, and presumptions.