Preheat the oven to 350 degrees and line 2 cookie sheets with parchment paper. In a medium bowl, combine flour, oats, baking soda, cornstarch, salt, and cinnamon.
In the bowl of your stand mixer (or a large bowl) beat butter and both sugars for 3-5 minutes until light and fluffy. Beat in egg and vanilla until well incorporated, then slowly mix in flour mixture until dough comes together. Fold in white chocolate chips and craisins.
Scoop out rounded tablespoons of dough and place at least 2 inches apart on prepared cookie sheets. Bake for 10-12 minutes or until edges are just beginning to brown, then remove from oven and let cool for 5 minutes on cookie sheet before removing to wire rack to cool completely.