Preheat the oven to 350-degrees and line a baking sheet with parchment paper.
Cream together the butter and sugar in a large mixing bowl.
Beat in the egg and vanilla.
Stir in the oats, baking soda, salt and flour, then fold in the white chocolate chips and dried cranberries.
Drop the cookie dough by rounded tablespoons onto the prepared sheet, about 1 1/2 inches apart.
Bake until golden brown, about 10-12 minutes.
Remove and cool 5 minutes before removing to a cooking rack.