Preheat your oven to 350°F and prepare a 9x13” baking pan with non-stick spray and parchment paper (see Note 1).
In a large bowl, beat together the butter and sugars until combined and fluffy. Beat in the egg yolks and vanilla extract. Then beat in the baking soda, baking powder, and salt.
Add the flour and use a large spoon or spatula to mix the dough together. Stir in 1 ¾ cup (341g) of the chocolate chips (the rest will go on top).
Spoon the dough into your prepared baking pan. Use the spoon to evenly spread and gently flatten the dough. Sprinkle the remaining ¼ cup (49g) of chocolate chips on top and gently press them into the dough.
Bake the bars at 350°F for 25-30 minutes, or until the edges are lightly browned and the center no longer looks wet.
Allow the bars to cool completely in the pan, on a cooling rack. If you’re feeling eager to dig in (and you don’t need the bars to look pretty) go ahead and scoop a spoonful out to eat warm.
Once the bars are cool, carefully lift the whole thing up and out of the pan (use the parchment paper “tabs”). Slice into rectangles or squares, sprinkle with a little flakey sea salt if desired, and enjoy!
Store leftovers in airtight container at room temperature.
