Beat cubed cold butter for 2 minutes until creamy
Add brown and granulated sugar; beat 2-3 more minutes
Add egg, yolk and vanilla bean paste; mix 3-4 minutes
In a separate bowl, whisk dry ingredients together
Gradually mix dry ingredients into wet mixture, then fold in chocolate
Scoop tall 6oz dough balls and freeze 2 hours or overnight
Bake at 350°F for 16-18 minutes with 3-4 cookies per tray, spaced well
Let cool and serve