In a mixing bowl whisk together the flour, baking soda, cornstarch and salt until well combined. Set aside for now.
2¼ cups (270 g) all purpose flour, 2 teaspoons cornstarch, 1 teaspoon baking soda, ½ teaspoon salt
Add the cubes of butter into a large mixing bowl fitted with a paddle attachment. Add the light brown sugar and granulated sugar. Mix the butter and sugars on medium speed for 2 - 3 minutes or until the butter and sugars are well combined.
¾ cup (170 g) cold unsalted butter, cubed , 1 cup (200 g) light brown sugar , ¼ cup (50 g) sugar
On low, cream in the egg, egg yolk and vanilla extract until smooth and well combined. With the mixer on low, add the dry ingredients into the wet a little at a time. Mix until just combined. Gently fold in the dried cranberriesand white chocolate chips until well combined.
1 large egg, room temperature, 1 large egg yolk, room temperature, 2 teaspoons (10 ml) vanilla extract , 1 cup (170 g) white chocolate chips, 1 cup (160 g) dried cranberries
Cover the cookie dough and transfer to the fridge to chill for 1 - 2 hours. About 30 minutes before you would like to bake the cookies, preheat the oven to 350 F (177 C). Line 1 - 2 large baking sheet(s) with parchment paper. Using a medium cookie scoop (2 tablespoons, 30 ml), scoop the white chocolate cranberry cookie dough into balls and place them onto the lined baking sheet about 3 inches (8 cm) apart. Bake for 10 -12 minutes until the edges are lightly golden brown and tops of the cookies are set. If you would like, add a few more white chocolate chips to the tops of the cookies while they are still hot. Cool the white chocolate and cranberry cookies on the baking sheet for 5 minutes. Then transfer to a cooling rack to cool completely to room temperature and enjoy.