Preheat your oven to 350°F (175°C) and prepare an 8x11 inch pan by lining it with foil, allowing overhang.

In a large mixing bowl, combine melted butter, light brown sugar, egg, and vanilla extract until smooth.

In another bowl, whisk together all-purpose flour, baking powder, and salt. Gradually fold this into the wet ingredients until well incorporated.

Gently fold in dried cranberries and white chocolate chips until evenly distributed.

Spread the batter into the pan and bake for 18-22 minutes until golden and a toothpick comes out clean. Cool slightly before transferring to a wire rack.

Prepare the frosting by beating cream cheese and butter until smooth, then mix in powdered sugar and vanilla until fluffy.

Once bars are cool, spread frosting generously on top. Optionally, garnish with more cranberries and white chocolate chips.

Slice into squares and serve. Store in an airtight container in the fridge for up to a week or freeze for longer storage.