Preheat your oven to 375ºF. Line 2 large baking sheets with parchment paper.
In a medium sized bowl, sift together flour, baking powder, baking soda, and salt. Set aside.
Beat the butter and sugar in a large mixing bowl until creamy smooth (about 3 minutes).
Add the first egg and beat on low-medium speed until fully incorporated. Repeat with the second egg. Add vanilla. MIxture will be soft and creamy
Add flour mixture to the mixing bowl. On low speed, pulse a few times to blend flour into creamed mixture. Low speed to prevent flour from exploding in your face.
Stir in the walnuts and chocolate chips.
Form and place eight 6-ounce rough/messy balls of cookie dough into your lined baking sheet. If you have a scale, weigh the dough then divide into 8-12 cookies. Each one will be approximately 4-6 ounces, as a general goal/guideline. Also, if the edges of the cookie dough ball are rough/not smooth, that’s better. I use 2 tablespoons In my experience, if you like craggly crispy tops, it’s best if you barely mush it together and smack it onto the pan.
At this point, if your dough seems like it has softened due to your kitchen's temperature or too much handling with hands, refrigerate the dough-balls for about half an hour before baking. Because of the relatively high flour content in this recipe, the dough tends to be pretty stiff and doesn’t require chilling.
Pop the pan(s) into the oven for 12-16 minutes. This time variation depends on your oven (I’m using conventional top and bottom heat, not convection) as well as whether or not you chilled your dough (and for how long). I recommend checking (look, don’t touch) the cookies every minute after hitting the 11 minute mark. Ideally, you want patches of deep golden brown and lighter golden brown.
No matter what, you need to let these cookies set! Similar to steak, you’ve gotta take the cookies out while they’re technically a bit undercooked, and let them finish cooking in the still-hot pan in order to achieve the cooked-but-gooey center. The amount of walnuts/chocolate chips will make it hard to really check the inside without just breaking a cookie in half.
If you need to reuse your baking sheet for the second batch of 4-cookies, you can do so. Just make sure the pan is clean of grease and has cooled down before you place the dough-balls on it.