1. Heat the oven to 350°F (175°C). Line a 9×13 inch baking pan with parchment paper, leaving some overhang on the long sides.

2. In a bowl, combine graham cracker crumbs, granulated sugar, and salt. Stir in melted butter until the mixture looks like damp sand. Press firmly and evenly into the prepared pan and bake for 8 to 10 minutes, until lightly golden. Let cool slightly.

3. Beat softened cream cheese until smooth. Add granulated sugar and beat until fluffy. Mix in eggs one at a time on low speed, just until combined. Blend in sour cream, vanilla, and lemon juice until the batter is silky.

4. Pour the cheesecake mixture over the warm crust and smooth into an even layer.

5. In a small saucepan, combine diced strawberries, strawberry jam, and lemon juice. In a separate bowl, whisk cornstarch and water until smooth, then stir into the pan.

6. Cook the strawberry mixture over medium heat, stirring often, until thickened and glossy and the berries have softened but still hold some shape, 3 to 5 minutes. Remove from heat and cool for a few minutes.

7. In a mixing bowl, stir together flour, brown sugar, and salt. Cut in the cold butter with a pastry cutter or your fingers until coarse crumbs form. Fold in the crushed freeze-dried strawberries if using.

8. Gently spoon the warm strawberry mixture over the cheesecake layer and spread evenly. Sprinkle the streusel crumbs over the top, leaving some larger clumps for extra crunch.

9. Bake for 25 to 28 minutes, until the edges are set, the center has only a slight wobble, and the topping is lightly golden.

10. Cool the pan completely at room temperature, then chill for at least 2 hours, or until very cold and set.

11. Use the parchment overhang to lift the slab onto a cutting board. Slice into 16 bars (or smaller pieces) with a sharp knife, wiping the blade clean between cuts. Serve chilled or slightly cool.