Make dry batter: In a bowl mix all purpose flour, baking soda, baking powder, corn starch and espresso powder mix well and set aside.
Make wet batter: In a stand mixer bowl or a mixing bowl crack in an egg, add the egg yolk. Add brown sugar and beat for 2 min on medium speed until light in color, add in granulated sugar , and beat for 1 min until well combined. Add in cold butter cubes and mix for 2-3 min until well combined. Add vanilla bean paste . And mix to combine.
Gradually add dry batter to the wet batter , add in chopped walnuts and chocolate chips. Mix the dough with a spatula until just combined. At first it's a little hard to mix but it will eventually come together. Do not over mix the batter.
Make 6 ounces tall cookie dough balls and place them on a prepared baking sheet. Freeze the dough balls for 30-40 min.
Preheat oven to 350 F. Do not place more than 4 cookies onto one baking sheet spacing them evenly. Bake the cookies straight from freezer for 15-18 min or until crispy from the edges and soft from center. Let cool for 1 hour before serving and enjoy.
