Best flour for making soft and chewy chocolate chip cookies?

I've had the best luck with all-purpose flour when I want cookies that stay soft and chewy, but the real trick isn't just the flour - it's how you use it. All-purpose typically runs around 10-12% protein, which gives you enough gluten development for structure without making things tough and cakey. The key is not to overmix once you add the dry ingredients, since that's what toughens cookies more than anything else.

If you want to push softness even further, you can blend all-purpose with a bit of cake flour (which has lower protein, around 7-8%). A ratio of maybe 3 parts all-purpose to 1 part cake flour keeps your cookies tender while still holding their shape. Some people swear by bread flour for chewiness, but honestly that seems backwards to me - it just makes them denser. What actually matters more is underbaking slightly and letting the residual heat finish them on the cooling sheet, plus not skipping the brown sugar, which holds moisture way better than white sugar.

One more thing: make sure your flour isn't packed down when you measure it. Spoon it into your measuring cup and level it off rather than scooping straight from the bag, since scooping compacts it and you'll end up with more flour than intended. That extra flour dries cookies out fast. Store them in an airtight container with a slice of bread if you want to keep them chewy for a few days - the bread gives up its moisture to the cookies.