Preheat your oven to 350°F (175°C). Line a 9x9 inch baking pan with parchment paper, leaving some overhang for easy removal later.
In a mixing bowl, combine the graham cracker crumbs, melted butter, and sugar. Mix until well combined and the mixture resembles wet sand.
Press the graham cracker mixture firmly into the bottom of the prepared baking pan to form an even crust. Bake in the preheated oven for 10 minutes, then remove and let cool slightly.
In a separate bowl, beat the softened cream cheese with an electric mixer until smooth. Gradually add the powdered sugar and vanilla extract, mixing until fully incorporated.
Add the eggs one at a time, mixing well after each addition. Be sure not to overmix.
Gently fold in the sour cream, lemon zest, and mixed berries, saving a few for topping.
Pour the cheesecake mixture over the cooled graham cracker crust. Smooth the top with a spatula.
Bake in the oven for 25-30 minutes, or until the edges are set but the center is still slightly jiggly.
Once done, remove from the oven and let it cool completely at room temperature, then refrigerate for at least 3 hours or overnight for the best texture.
When ready to serve, use the parchment overhang to lift the cheesecake bars out of the pan. Cut into squares, sprinkle with reserved berries on top, and enjoy!
Notes
Plate the bars on a dessert platter and garnish with fresh berries and a dusting of powdered sugar for an elegant finish.