Preheat oven to 350.
In the bowl of a stand mixer, cream butter and both sugars on speed 2 for 4 minutes.
Add eggs, one at a time, beating to incorporate each.
Add vanilla, and mix.
Add baking powder, baking soda, salt, and flour, and mix until incorporated.
Add oatmeal, stirring until combined.
Add white chocolate chips, dried cranberries, and pecans, stirring until incorporated.
Grease the bottom and sides of a 13x9 pan with butter.
Transfer batter to pan, using the back of a spoon or spatula to spread evenly in the pan.
Bake for 25-30 minutes, or until golden brown.
Cool in pan on a wire baking rack.