Set your oven to 350°F and line a 9 × 13-inch pan with parchment paper, leaving enough overhang on two sides to lift the bars out easily.

Combine the graham cracker crumbs, melted butter, sugar, and salt in a bowl, stirring until the mixture is evenly moistened.

Press the crumb mixture into the bottom of the prepared pan, spreading it into an even layer. Bake for 8 minutes, then let it cool completely.

Reduce the oven temperature to 325°F.

In a large mixing bowl or the bowl of a stand mixer fitted with a paddle attachment, beat the cream cheese and sugar together on medium-high speed until smooth and fluffy, about 5 minutes. Be sure to scrape down the sides of the bowl as needed.

Add the eggs one at a time, mixing thoroughly after each addition.

Mix in the sour cream, lemon zest, vanilla extract, and salt, blending until everything is fully incorporated.

Pour the cheesecake batter over the cooled crust, spreading it evenly.

Bake for 40–45 minutes, or until the center of the cheesecake is just set. Remove from the oven and allow to cool to room temperature for about 2 hours. Cover the pan with plastic wrap and refrigerate for at least 4 hours or overnight.

In a medium saucepan, whisk together the sugar, cornstarch, lemon juice, and water. Use ⅓ cup water if using fresh berries or ¼ cup if using frozen.

Heat the mixture over medium heat until it begins to thicken, stirring constantly, about 1 minute.

Add the berries and gently stir, cooking for 5–6 minutes until they release their juices and start to bubble. Remove from heat and let the sauce cool completely.

Once chilled, use the parchment paper overhang to carefully lift the cheesecake out of the pan. Transfer it to a cutting board.

Slice into 12–16 bars, cleaning your knife with a damp towel between cuts for neat edges.

Spoon the cooled berry sauce over the bars just before serving.