In a medium bowl, sift together the dry ingredients. Set aside.

In the bowl of a stand mixer or in a medium bowl with a hand mixer, cream the butter and sugars until light and fluffy, 2-3 minutes.

Add the egg and vanilla extract, mixing until just combined, scraping down the sides as needed.

With the mixer on low, slowly add the dry ingredients, mixing until combined.

Add the chocolate chips or chunks and mix until just evenly distributed. For gooey puddles of chocolate on top, reserve some of the chocolate chips/chunks for on top.

Using a medium cookie scoop, drop 2 tablespoon-size balls of dough onto a parchment-lined baking sheet, close together. Press the reserved chocolate chips for on top of the balls of cookie dough.

Chill the cookie dough in the fridge for at least 1 hour or the freezer for at least 20 minutes (pictured here).

When ready to bake, preheat the oven to 350°F. Place the cookie dough balls at least 2 inches apart on a parchment-lined baking sheet and bake for 10-12 minutes. If the dough has been frozen for longer than an hour, add 1-2 minutes to your baking time. Take care not to overbake cookie dough. Pull them out when the edges look just set, but the centers still look just a bit underbaked. The cookies will continue baking as they cool.

Optional: As soon as the cookies come out of the oven, use a large round cutter or the ring of a large mason jar (larger than the diameter of the cookie) to scoot each cookie into a perfect circle. This method also helps make the centers of the cookie puff up, adding to the chew factor.

Let cool on the baking sheet for 3 minutes before carefully transferring to a wire rack to cool completely.