Order the Cracklain-which is a sweet, brioche-type dough with chunks of sugar mixed in and on top…read more All their other stuff is good too (croissants, cakes, etc). You will need to get there in the morning though for best (or any) selection.
We have Belgian relatives so all the patisseries were pre-scouted for us. They think this is the best, and after trying many we agree.
There is a weekly farmer's market nearby (3pm on Wednesdays). You'll need to reserve your food from De Baere if you are going to come this late.