Line the pan with parchment, leaving overhang for easy lifting. Mix crumbs, sugar, and melted butter until evenly combined. Press firmly into the bottom of the pan and bake briefly to set.

Beat cream cheese on low speed until smooth. Add sugar and mix gently. Add eggs one at a time, mixing slowly. Stir in sour cream, lemon zest, lemon juice, vanilla, and salt. Mix only until combined.

Pour the cheesecake filling over the cooled crust and smooth the surface. Spoon strawberry puree or sauce in small dollops across the top.

Use a knife or skewer to gently swirl the strawberry into the lemon cheesecake layer. Keep the motion light to preserve definition.

Bake until the edges are set and the center has a slight jiggle. Overbaking will dry out the bars.

Allow bars to cool completely at room temperature, then refrigerate for several hours until fully set before slicing.