In a medium bowl, mix together the strawberries, granulated sugar, lemon juice, lemon zest, 1/4 teaspoon of the vanilla and the salt. Cover and let macerate in the refrigerator for at least 6 hours or ideally overnight.
Place the strawberry mixture in a blender. Add the wine or apple juice and blend until completely smooth. Refrigerate until ready to serve.
Preheat the oven to 375 degrees F. Lightly grease a baking sheet.
For the croutons, spread the cubed pound cake on the prepared baking sheet and bake until golden brown and crispy, flipping the cubes halfway through, about 10 minutes. Set aside to cool.
In a medium bowl, add the heavy cream, mascarpone, powdered sugar and the remaining 1/4 teaspoon vanilla. Using an electric mixer, whisk on medium speed until soft peaks form. Be careful not to over-beat.
To assemble, divide the soup into 4 teacups or small bowls. Place a dollop of cream on each one and scatter the croutons around the top. Serve immediately.