Add butter to the bowl of a stand mixer fitted with the paddle attachment. You could also use a large bowl with an electric hand mixer. Beat until creamy on medium-high speed.

Add sugars and beat until well combined. Add eggs and vanilla extract, beating until combined.

In a separate bowl, whisk together flour, cornstarch, baking soda, salt, and ground cinnamon.

Turn mixer on low, then gradually add flour mixture to the wet ingredients until combined. Add oats, white chocolate chips, and cranberries, stirring until just combined.

Cover bowl with plastic wrap and place in the refrigerator. Chill for at least 30 minutes, up to overnight.

When ready to bake, preheat oven to 350˚F. Line baking sheets with silicone mats or parchment peper.

Scoop out dough by 2 Tablespoon scoops, forming them into balls (I find a cookie dough scoop works best here!). Place on the lined baking sheets, spacing them about 2 inches apart.

Bake for 12 to 14 minutes, until the edges are golden brown. The centers will look a little soft, but this is ok. They will finish cooking on the baking sheets.

Cool completely on the baking sheets before serving. If you try to remove them when they are too hot, they will fall apart!