Heat oven to 350 degrees F (180 degrees C). Line a large cookie sheet/baking pan with parchment paper or a silicone mat.
Beat Butter (3/4 cup), Dark Brown Sugar (1 cup), and Granulated Sugar (1/4 cup) in a large bowl with mixer until light and fluffy.
Blend in a whole Egg (1) plus egg yolk, and Pure Vanilla Extract (2 teaspoon). Scrape down the sides of the bowl as needed. Add All-Purpose Flour (2 cup) plus 2 Tbsp, Corn Starch (2 teaspoon), Baking Soda (1 teaspoon), and Salt (1/2 teaspoon), mix well. Stir in White Chocolate Chips (3/4 cup) and Dried Cranberries (3/4 cup).
Drop rounded spoonfuls, about 2 Tbsp of dough, 1-1/2 inches apart onto baking sheets. Add a few white chocolate morsels and cranberries to the tops of the cookies for a prettier cookie.
Bake for about 9-12 minutes.
Cool on baking sheets for about 1 minute and remove to wire racks to cool completely.