In a medium saucepan heat one cup of mixed berries, 2 tablespoons sugar and lemon juice over medium heat, until the blueberries begin to burst and the other berries break down, about 10 minutes.
Remove from off heat and stir in the pinch of salt.
Place half the berry mixture in a blender and puree until smooth. Return the sauce to the saucepan and stir well to combine with remaining fruit. Allow to cool slightly.
Meanwhile, in a medium bowl crush 3/4 cup of mixed berries with remaining 2 tablespoons sugar using a fork, until slightly chunky and loose.
In a large bowl or stand mixer, using a balloon whisk or hand-held mixer, beat the cream at medium speed until soft peaks form.
Gently fold the crushed berries into the whipped cream. Refrigerate until ready to serve.
To serve: spoon 2 tablespoons of the sauce into each of 6 parfait or rocks glasses.
Top with a scoop of vanilla ice cream, a sprinkling of crushed graham crackers, and a pinch of lemon zest.
Then add a scoop of the raspberry sorbet and another 2 tablespoons of the sauce.
Top with a dollop of whipped cream and finish with a sprinkling of the graham crackers and another pinch of zest. Serve immediately.