Preheat your oven to 350°F (175°C) and grease a 9×13 inch baking pan.

In a large bowl, beat the butter, brown sugar, and granulated sugar until light and fluffy. Add eggs one at a time, mixing well after each.

In another bowl, whisk together flour, baking powder, and salt. Gradually add to the wet mixture, stirring until just combined. Fold in cranberries and white chocolate chips.

Spread the batter evenly in the prepared pan and bake for 20-25 minutes or until golden brown; a toothpick inserted should come out clean.

Allow the bars to cool completely before frosting with a mixture of cream cheese and powdered sugar.

Slice into squares and serve.