Preheat oven to 350 degrees. Prepare two large baking sheets with a silpat or parchment paper.
In a small mixing bowl, combine the flour, baking powder and salt. Stir to fully mix and set aside.
Melt the 1 ½ cups chocolate chips and the butter (combined) using double boiler, a metal mixing bowl over a saucepan of boiling water OR the ‘melt’ function of a microwave. Stir as needed during the melting process, until smooth texture. Do not overcook.
Using a mixer, lightly beat the eggs (alternatively a whisk may be used).
Mix in the sugar.
Add the melted chocolate, and vanilla extract, mixing until fully combined.
Gradually stir in dry ingredients to fully combine.
Stir in the remaining 1/3 cup of baking chips.
Place tablespoon amounts of the cookie dough on the prepared baking sheets with 2 inch spacing in between them. Bake for 10 minutes and check for doneness (the cookies will have some cracks in them, be glossy but not dry; do not overcook); if still too soft allow to bake a few more minutes. Note: different baking sheet types (dark or light colored) make a difference of a few minutes in the baking duration.
Allow cookies to cool for 5 minutes on the baking sheet, remove and place on cooling rack to cool completely.