Whatever flour you are using. Use more of it. If it's premixed and you are not sure, then cornstarch will do. You will find that you need very little to stiffen it up.
I had a look at your blog. Very interesting. I have tried baking a few times with reasonable success, although I tend not to follow recipes and just figure it out myself. I think your problem with muffins might be that the mix is too liquid. Since the container is smaller the muffins rise up...
Hi
I am an amateur cook from South Africa who loves to experiment with any and everything. I have started up a blog for jotting down the recipes I experiment with. I look forward to interacting with everyone here.
http://mikrotiksa.com/evo//blog5.php