Preheat oven to 375 degrees F and line a baking sheet with parchment paper.: The oven should be at the right temperature so cookies set quickly at the edges while the centers remain tender. You want to feel a steady warmth from the oven when you open it, and the parchment prevents sticking and promotes even browning. A common error is skipping preheating which leads to uneven spread and inconsistent texture, so always wait until the oven reads the correct temperature.
In a medium bowl, whisk together the flour, baking soda, baking powder, and salt. Set aside.: After whisking you'll see a uniform pale mixture with tiny specks of salt. This step evenly distributes leaveners and seasoning so pockets of soda do not create bitter spots. If you skip thorough mixing you may get uneven rise or salty pockets, so take a minute to combine until it looks homogeneous.
In the bowl of a stand mixer or using a hand mixer, cream together the butter and sugars until light and fluffy. Add the eggs and vanilla. Mix until well combined.: As you cream, notice the butter and sugars becoming paler and aerated, this incorporates air that helps with texture. When eggs go in, the mixture will become silkier and give off a sweet, buttery aroma. Over mixing after adding flour can create toughness, so stop once the mixture looks smooth and uniform.
Slowly mix in the flour mixture until combined. Add the chocolate chips and stir until just combined.: As you fold in the flour, the dough will thicken and become slightly tacky. Working slowly avoids overworking gluten which would make cookies chewy in a dense, undesirable way. When the chocolate chips are added, they become scattered pockets of dark color in the dough. Stir only until you no longer see streaks of flour; over stirring can break chips and warm the dough too much.
Scoop 1 1/2 tablespoons of dough onto the baking sheet 2-inches apart from each other. Bake for 8-10 minutes or just until the edges start to brown. You can make them bigger if you like. Remove from oven and let them sit on the baking sheet for a few minutes. I like to press a few chocolate chips on top at this point to make them look like bakery cookies. I also sprinkle with a little flaked salt to bring out the flavors.: When scooping, aim for uniform mounds; you will hear a quiet soft thud as dough lands on the parchment. As they bake, the smell will become warm and caramelized, and the edges will darken slightly while centers still jiggle a touch. The few minutes on the hot sheet finish cooking internally and make them easier to transfer. Avoid leaving them in too long, or they will lose the soft center texture you want.