In the bowl of a stand mixer, beat together the butter and brown sugar with the paddle attachment until light and fluffy. Beat in the vanilla and egg to combine. Lastly, beat in the flour, cornstarch, baking soda and pinch of salt until a soft dough has formed. Stir in the cranberries and white chips by hand.

Refrigerate the cookie dough for AT LEAST 1 HOUR. You can chill it overnight if you'd like, but one hour chill time is mandatory to prevent cookies from spreading and to create that light, soft and chewy texture.

Preheat oven to 350°F. Line two baking sheets with silicone liners or mist lightly with cooking spray. Remove chilled dough from fridge and roll into Tablespoon-sized balls. Place onto the cookie sheets about 1-2" apart from one another.

Bake for approximately 8-10 minutes, rotating pans halfway through baking time to ensure an even cook. Cookies may appear slightly undone, but do not over-bake them! They will continue to set up more as they cool. Allow cookies to set on the baking sheets for about 10 minutes or so before carefully transferring to a wire rack to cool completely. If you'd like to make them prettier, garnish cookies with additional white chips on top of still-warm cookies before serving.