Whisk together flour blend, baking soda and salt to aerate and combine; set aside.

Place brown sugar, sugar and minced mint in bowl of standing mixer or a regular mixing bowl. Use flat paddle attachment for stand mixer or just the regular beaters for a hand held mixer and beat the sugars and mint on medium speed for about 2 minutes. The rough sugar particles will be grinding against the mint leaves extracting all that cool minty flavor that we want.

Add the butter and continue beating on medium-high speed until creamy, about 3 minutes, scraping down bowl as needed. Fat is a great carrier of flavor and the aromatic mint oil will combine with the butter at this point, setting the stage for the most awesomely fresh mint chocolate chunk cookies you have ever tasted. Beat in vanilla, then beat in eggs one at a time allowing each one to be incorporated before adding the next. Beat in the dry mixture until a few streaks of flour remain. Add chocolate and beat just until combined. Cover the bowl and chill for at least 4 hours but preferably overnight.

Position racks in upper and lower thirds of oven. Preheat oven to 375°F/190° Line two baking sheets with parchment paper.

Form golf ball sized balls and place the cookies 8 per pan, spaced evenly apart. No need to press them down.

Bake for about 12 to 15 minutes or until lightly browned with the edges firmer than the centers, which should be soft. The cookies firm up tremendously upon cooling. Cool cookies completely on pans set on racks. (Make subsequent batches with cooled pans). Cookies are best served the same day but may be stored at room temperature in an airtight container for up to 3 days.