In a large bowl, beat butter and sugars until light and fluffy, approximately 1-2 minutes
Add in vanilla extract, egg and egg yolk and mix until well combined.
Combine dry ingredients in a separate bowl, then add to wet ingredients and stir until combined. Do not over mix.
Scoop cookie dough with ice cream scoop onto baking sheets that have been lined with wax paper or a silicone baking mat. Cookie dough balls should be slightly larger than a golf ball, approximately 1/4 cup. Make sure to leave ample room on cookie sheet, as cookies will spread as they bake.
Cover cookie sheets and place into refrigerator for at least 30 minutes. 1-2 hours is ideal, and you can leave them in up to 48 hours.
When ready to bake, remove cookie sheets from refrigerator and let sit out while preheating oven to 350 degrees F.
Bake cookies for approximately 10-13 minutes or until starting to brown around edges. Centers may look slightly undercooked. Remove baking sheet from oven and allow cookies to cool on baking sheet for 15-20 minutes. Remove, serve and enjoy!