01 - Preheat oven to 325°F (163°C). Line a 9x9-inch baking pan with parchment paper, allowing an overhang for easy removal.
02 - In a medium mixing bowl, combine graham cracker crumbs, granulated sugar, and melted butter. Press the mixture firmly and evenly into the bottom of the prepared pan to create the crust.
03 - Using an electric mixer, beat the softened cream cheese and granulated sugar in a large bowl until smooth and creamy. Add the eggs one at a time, mixing thoroughly after each addition. Blend in vanilla extract and sour cream until the mixture is fully combined.
04 - Pour the cheesecake filling evenly over the prepared graham cracker crust. Smooth the top with a spatula. Bake for 40 to 45 minutes, or until the center is just set and the edges appear lightly golden.
05 - Remove from the oven and let cool to room temperature. Transfer the pan to the refrigerator and chill for a minimum of 3 hours until thoroughly set.
06 - Once chilled, top the cheesecake evenly with chopped strawberries and blueberries in a decorative pattern. Drizzle with melted white chocolate if desired.
07 - Lift the cheesecake out of the pan using the parchment overhang. Slice into 16 bars and serve chilled.