i personally think that you should bake them on a lower temperature for less time, so that they don't cook as much so they come out chewier.
(but don't cook them for too much less time, or they wont be cooked at all)
i suggest that you cook them for about 4 minutes less.

Hi Jeni,

I love baking cookies and I don't know what sort of recipe you're using but I like to use the American style ones to get big, moist, chewy cookies. I'm not sure I should be linking to a recipe from this site, but if you search in Google for chewy cookie recipes, there should be plenty around!

If you'd rather just tweak the recipe you already have though, from what I've heard, adding an extra egg yolk, using more or all brown sugar (retains more moisture than white whilst cooking apparently) or maybe reducing the flour a little might help your cookies remain moist and come out chewy.

I also agree with cooking crazy that you might want to lower the temperature to cook the batter more slowly - think how slow cooked meat comes out all moist and tender! Say maybe knock about 10degC off the recommended temp. Another trick is to only cook them until they are *just* dry and remove them from the oven but allow them to cool on the baking tray as they will continue to cook and 'set' as the tray cools down.

Hope this helps!

Stan

I'd be interested in seeing what recipe you're using, as it would make it easier to give advice.

I would say, though, that if you want a chewy cookie, it helps to look at the fat called for in the recipe.  Butter will make the cookie spread further, and add a bit of a crispness.  Vegetable shortening (mm I hope that is what it is called here in the UK- I'm originally from the US.  Solidified vegetable fat) is often used in the US to make cookies more chewy. 

For chocolate chip cookies, I still use butter, as I like the flavour, but I cook them for a shorter time than is called for.  This still gives me a slightly chewy cookie, just with a bit of a crispness around the edges.