01 - Preheat oven to 325°F (163°C). Line a 9x9-inch baking pan with parchment paper, allowing overhang for easy removal.
02 - Combine graham cracker crumbs, sugar, and melted butter in a medium mixing bowl. Press mixture evenly into the prepared pan to create a compact layer.
03 - In a large bowl, beat cream cheese and sugar with an electric mixer until smooth and creamy. Add eggs one at a time, mixing thoroughly after each addition. Blend in vanilla extract and sour cream until fully incorporated.
04 - Spread cheesecake batter over the crust, smoothing the top for an even layer.
05 - Bake for 40 to 45 minutes or until the center is set and edges appear lightly golden. Remove from oven and allow to cool to room temperature.
06 - Refrigerate for at least 3 hours to enable bars to fully set.
07 - Top chilled surface with chopped strawberries and blueberries to form a celebratory pattern. If desired, drizzle with melted white chocolate. Slice into individual bars and serve chilled.