Instructions

1. Combine the dry ingredients: In a medium sized mixing bowl, whisk together the all-purpose flour, corn starch, baking powder, and fine sea salt until combined well. Set aside.
2. Cream: Add the unsalted butter, granulated white sugar, and light brown sugar to a large mixing bowl. Cream using and electric hand mixer (or stand mixer fitted with the paddle attachment) on medium-high speed, scraping the sides of the bowl as needed, until the mixture is light and fluffy – about 2-3 minutes.
3. Add the wet ingredients: Add the egg, vanilla extract, and Greek yogurt and continue beating on medium speed until evenly combined – about 30-45 seconds.
4. Sift in dry ingredients: Using a fine mesh strainer, sift in the dry ingredients and mix on low speed, scraping the sides of the bowl as needed, until everything is just combined. Do not overmix.
5. Fold in mix-ins: Fold in the white chocolate chips, dried cranberries, and dried blueberries using a rubber spatula. Cover the bowl with cling wrap or aluminum foil and chill in the refrigerator for 2-3 hours and up to 2 days (see notes*).
6. Prepare for baking: Preheat oven to 175°C / 350°F. Line two baking trays with silicone baking mats or parchment paper/nonstick cooking paper.
7. Scoop and shape: Remove the cookie dough from the refrigerator. Scoop the dough using a trigger release scooper (2 tablespoons for medium sized cookies, and 2.5 to 3 tablespoons for medium-large cookies) and gently roll into balls. The dough will be wet and sticky so work quickly. Place the dough balls on the prepared baking trays, leaving 3-inch space between each dough ball.
8. Bake: Bake one tray at a time on the middle rack for 13-15 minutes, or until the edges start to turn golden brown.
9. Cool: Remove the tray from the oven and allow the cookies to rest for 5-10 minutes in the pan. They will still look slightly uncooked and wet but will firm up as they cool. Then transfer the cookies to a wire cooling rack to finish cooling completely. Enjoy now, or store in a sealed airtight container in a cool dry area for 3-4 days.