Preheat oven to 350°F (175°C). Line a 9x13-inch baking pan with parchment paper.
In a large bowl, whisk together melted butter, brown sugar, and granulated sugar until smooth.
Beat in eggs and vanilla. Stir in ground ginger and salt.
Fold in flour until just combined. Stir in white chocolate chips and dried cranberries.
Spread batter evenly in prepared pan and bake for 22–25 minutes or until golden brown. Let cool completely.
For the frosting, beat cream cheese, powdered sugar, and vanilla until smooth and creamy.
Spread frosting over cooled bars. Sprinkle with chopped cranberries and drizzle with melted white chocolate.
Refrigerate 1 hour before slicing into triangles. Serve chilled or at room temperature.