Chocolate Chip Cookies At Home

I've been craving chocolate chip cookies ever since having one from the Cookie Guru on Monday night. I haven't made any at home since I was a kid so I decided to get a shot. I didn't have much time so after a really quick search, I decided to go with Giada's recipe for Hazelnut Chocolate Chip Cookies (only changes being reducing the amount of sugar by at least 1/4 and using a chocolate toffee bar from Whole Foods instead of the Heath Bar, Heath Bar would have been better) since I had some hazelnuts and oatmeal in my pantry that I wanted to use up. Like most things that I bake, it was good, but not amazing. A couple of issues that seem to be a common theme with most of my baking: they are a little dense and crumbly and the ones on the bottom rack seemed to be overcooked on the bottom and undercooked on the top (not pictured, the ones that turned out better are below). They didn't quite have the moist, chewy texture of the cookies that I had on Monday night.  I'm not sure how to fix the dense issue; it could be because I omitted baking soda from the recipe because I didn't have any, or because my baking powder is too old, or because the oatmeal and nuts just gives it a different texture. I'm also not sure how to fix the oven issue; since my oven is so small and narrow, I need to use almost all the racks when I make a batch of cookies according to the recipe, and inevitably the temperature is different on all racks. I suppose that if I had the patience, I should just do one rack at a time.