See, now this is how foodpickle should work. someone asks an intelligent question she actually wants an answer to, people try to give some good advice and she even says thank you!

Thanks everyone for your great tips and recipes much appreciated x

I love me some cookies! Here's a great chewy chocolate chip cookie. And I'm sure if you under cook it a bit, it'll be really gooey!

http://www.foodnetwork.com/recipes/alton-brown/the-chewy-recipe/index.html

The basic toll house recipe is a very good start. (http://www.verybestbaking.com/recipes/18476/Original-NESTL%C3%89-TOLL-HOUSE-Chocolate-Chip-Cookies/detail.aspx)

One issue you may have in the UK is selecting the right brown sugar. As I recall, most of the brown sugar there has pretty large crystals, which makes it difficult to properly cream the butter and sugar, which is key to getting the right texture. You want a pretty dark brown sugar with small crystals. If you can't find one that is suitable, you can easily make your own by adding molasses (dark treacle) to a fine white sugar (castor sugar). When you cream the butter and sugar you should end up with a smooth paste with no graininess when you rub a bit between your fingers.

I have successfully altered choc chip cookie recipes to amplify the "gooey" factor by subbing brown sugar for white and underbaking a bit. I like a crispier cookie myself, but I find that those two changes can really help. Also, if you're not averse to using it, shortening instead of butter will also keep your cookie softer.

If you google "Toll House cookie" you'll find what many think is the classic cookie recipe. See how it compares to the recipes you're using.

Good luck & happy baking!