For me, the perfect chocolate chip cookie has a crisp exterior and a chewy, melt-in-your-mouth interior. I get that result when I use cold butter in the mix and a hotter oven for the bake. Cut up a stick of butter from the fridge into 10-16 pieces. Keep that butter cold just until you’re ready to add. As with EVERY baked good you make, don’t over mix. It’s ok to have some lumps. In fact, finish mixing the dough by hand, kneading the last bits together like you would bread, but only for a few turns. With a colder dough, you’ll need a hotter oven. Most recipes will prescribe 350ºF for baking cookies, but I take mine up to 375ºF and I often use the convection setting. The last thing I do is to drop the sheet tray onto the counter hot from the oven. This compacts the hot dough in a lovely way. Try out these tips next time and see what happens. Who knows? You might hit on perfection!