Prep Oven & Pan: Preheat your oven to 350°F (175°C). Line an 8x8-inch or 9x9-inch metal square baking pan with parchment paper, leaving an overhang on the sides for easy lifting.

Whisk Butter and Sugars: In a large heatproof mixing bowl, whisk together melted butter, dark brown sugar, and granulated sugar vigorously for 2 minutes until glossy and combined.

Add Eggs & Vanilla: Whisk in whole eggs, extra egg yolk, and vanilla bean paste. Beat vigorously for 1 full minute until the batter turns lighter in color and forms ribbons—this builds the shiny papery crinkle crust!

Fold in Dry Ingredients: Switch to a silicone spatula and gently fold in the all-purpose flour, baking powder, and fine sea salt until just combined into a thick, glossy dough. Do not overmix.

Fold in Cranberries & White Chocolate: Gently fold in the fresh cranberries and white chocolate chunks until evenly distributed throughout the batter.

Spread & Bake: Transfer thick batter into the prepared pan, smoothing the top into an even layer with an offset spatula. Bake at 350°F for 24 to 28 minutes—the edges should be golden brown and pulling slightly from the pan, while the center remains slightly soft to the touch. A toothpick inserted into the center should come out with moist crumbs, not raw batter. Do not overbake!

Cool, Drizzle & Slice: Allow blondies to cool completely in the pan on a wire rack for 45 minutes to set into their fudgy texture. Drizzle with melted white chocolate and finish with flaky sea salt. Lift from pan using parchment overhang and slice into 16 perfect squares.