1. Preheat the oven to 350°F (175°C). Line a 9×9-inch baking pan with parchment paper, leaving an overhang on two sides to lift the bars out later.

2. In a large bowl, combine the fudge brownie mix, melted butter, eggs, water, 1 teaspoon of the vanilla extract, and the fine salt. Stir just until the batter is smooth and glossy; avoid overmixing so the brownies stay fudgy.

3. Spread the brownie batter evenly in the prepared pan. Bake for 22–28 minutes, or until the edges are set and a toothpick inserted in the center comes out with a few moist crumbs. Cool the brownie base completely in the pan on a wire rack.

4. Once the brownies are cool, beat the softened cream cheese in a mixing bowl until completely smooth and fluffy, scraping down the sides of the bowl as needed.

5. Add the powdered sugar, remaining 1 teaspoon vanilla extract, and lemon juice to the cream cheese. Beat until smooth and creamy with no lumps.

6. In a separate chilled bowl, whip the cold heavy whipping cream to soft peaks. Gently fold the whipped cream into the cream cheese mixture until fully combined and light, being careful not to deflate the mixture.

7. Spread the cheesecake mixture over the cooled brownie base, smoothing it into an even layer all the way to the corners.

8. Warm the strawberry jam slightly if needed so it loosens. Dollop spoonfuls of jam over the cheesecake layer, then gently swirl it through the surface with a knife or skewer without cutting into the brownie.

9. Sprinkle the diced fresh strawberries evenly over the top of the cheesecake and jam layer, pressing them in very lightly so they adhere.

10. In a medium bowl, stir together the crushed golden sandwich cookies, crushed freeze dried strawberries, and melted butter for the topping until the crumbs are evenly moistened and form small clumps.

11. Scatter the strawberry cookie mixture evenly over the strawberry layer, letting some larger clusters remain for extra crunch.

12. Sprinkle the mini marshmallows or marshmallow bits over the top of the crumbs, pressing gently so they stick to the surface.

13. Cover the pan tightly with plastic wrap or foil and refrigerate for at least 3 hours, or until the cheesecake layer is fully set and the bars are chilled through.

14. When ready to serve, use the parchment overhang to lift the entire slab of bars out of the pan. Place on a cutting board and slice into 16 squares with a sharp knife, wiping the blade clean between cuts for neat layers.

15. Serve the Strawberry Crunch Brownie Bars cold. Store any leftovers covered in the refrigerator for up to 4 days, or freeze individual bars for up to 2 months and thaw in the fridge before serving.