In a large bowl, stir together the oats, flour, baking powder, salt, baking soda, and cinnamon. Set aside.
In the bowl of an electric mixer, blend the butter and sugar together until light and fluffy, approximately 3 minutes. Add the eggs and then the vanilla.
With the mixer on low, gradually add the dry ingredients to the wet ingredients. Once mixed, add the white chocolate chips and cranberries. Mix just until combined.
Cover the bowl and chill for 1 to 2 hours.
Preheat the oven to 375 °F and grease or line baking sheets with parchment paper.
Using a 1-1/2 tablespoon scoop, roll dough into balls and place them on a prepared baking sheet, 12 to a pan. Lightly press each cookie to slightly flatten. I use the back of a measuring cup.
Bake for 9 to 11 minutes, turning the pan halfway through baking. Cookies are done when lightly browned on the edges. Remove the cookies from the baking sheet and allow them to cool on a cooling rack.
Once cool, store in an airtight container at room temperature or freeze.
This recipe was calculated using the exact brands and measurements I used to make this recipe. If you are following a strict diet please note changing anything will cause the nutritional info to change. My calculations are intended as a guide only.