Preheat your oven to 325 degrees.
Line a 9x13 baking pan with parchment paper (this will make for easier cutting and clean up).
In a large bowl, whisk together the flour, salt and baking soda. Then set aside.
In a saucepan, melt the butter and let it simmer for a minute. This will give it a delicious flavor!
Add the melted butter, brown sugar and sugar to the dry ingredients. Mix until combined.
Add in the egg, egg yolk and vanilla extract. Mix until well combined.
Stir in the chocolate chips and mix just until everything is combined. You do not want to over mix.
Take the dough out of the bowl and transfer it over to the lined 9x13 baking pan. The dough will be fairly firm. You’ll want to use your fingertips to spread it over the entire baking pan.
Bake for 20 minutes. At the 20 minute mark, make sure to watch closely. You want a lightly golden top. It is very important that you do NOT over bake. Once the bars are lightly golden (between the 20-25 minute mark), pull them out and let them cool.
After the bars have cooled, lift them out of the 9x13 pan with the paper underneath. Use a sharp knife and cut the bars into squares. Enjoy!