Step 1: Preheat your oven to 350°F (175°C). Line a 9x13-inch baking pan with parchment paper, leaving an overhang on the sides to easily lift the bars out later. Lightly grease the parchment paper.
Step 2: In a medium saucepan, melt the unsalted butter over medium heat. Once melted, remove from heat and let it cool slightly for a few minutes.
Step 3: In a large mixing bowl, combine the cooled melted butter with the granulated sugar and light brown sugar. Whisk vigorously until well combined and smooth.
Step 4: Whisk in the eggs one at a time, ensuring each egg is fully incorporated before adding the next. Stir in the vanilla extract.
Step 5: In a separate medium bowl, whisk together the all-purpose flour, baking powder, and salt. Gradually add the dry ingredients to the wet ingredients, mixing on low speed or by hand until just combined. Be careful not to overmix.
Step 6: Gently fold in 1 cup of the white chocolate chips and 1/2 cup of the dried cranberries. Distribute them evenly throughout the batter.
Step 7: Pour the batter into the prepared baking pan and spread it evenly. Bake for 25-30 minutes, or until the edges are golden brown and a toothpick inserted into the center comes out with moist crumbs, not wet batter.
Step 8: Remove from the oven and let the blondie base cool completely in the pan on a wire rack before frosting.
Step 9: In a large mixing bowl, using an electric mixer, beat the softened cream cheese and unsalted butter together on medium speed until smooth and creamy, about 2-3 minutes.
Step 10: Gradually add the powdered sugar, one cup at a time, mixing on low speed until fully incorporated. Then, increase the speed to medium-high and beat until light and fluffy, about 2-3 minutes.
Step 11: Beat in the vanilla extract and the fresh orange zest until just combined.
Step 12: Once the blondie base is completely cool, spread the cream cheese frosting evenly over the top.
Step 13: In a small microwave-safe bowl, melt the remaining 1/2 cup white chocolate chips in 20-second intervals, stirring after each, until smooth.
Step 14: Drizzle the melted white chocolate over the frosted bars.
Step 15: Immediately sprinkle the remaining 1/2 cup dried cranberries and the extra fresh orange zest evenly over the top of the drizzled white chocolate.
Step 16: Refrigerate the bars for at least 30 minutes to allow the frosting to set and the white chocolate drizzle to harden.
Step 17: Once chilled, lift the bars out of the pan using the parchment paper overhang. Cut into squares or rectangles using a sharp knife.