Preheat the oven to 350 degrees. Spray a 9x13-inch baking dish with nonstick spray or line with parchment paper.
Prepare the blondie layer: In a medium bowl, melt butter for one minute in the microwave or until melted; stir in brown sugar. Pour the butter and sugar into a large bowl and let cool to room temperature. Use an electric mixer to beat in the eggs and vanilla. In a separate bowl, whisk together the flour, baking powder, salt and cinnamon; gradually add the dry mixture to the butter mixture. Stir in the cranberries and chopped chocolate (batter will be thick).
Spread the blondie batter into the prepared pan. Bake for 18-21 minutes or until a toothpick inserted near the center comes out clean (do not overbake). Cool completely on a wire rack.
Prepare the frosting: In a large bowl, use an electric mixer to beat the cream cheese and powdered sugar until combined. Gradually add half of the melted white chocolate; beat until blended. Frost brownies. Sprinkle with chopped cranberries. Drizzle with remaining melted white chocolate. Let the frosting set (speed this up by throwing them into the fridge) then cut into bars- square or triangle-shaped. Store in the refrigerator until ready to serve.