In bowl, combine graham wafer crumbs, butter and 1 tbsp (15 mL) of the sugar; remove 1/2 cup (125 mL) and set aside. Press remaining crumb mixture firmly into bottom of 9-inch (23 cm) nonstick springform pan.

In bowl, combine puréed and mashed strawberries and remaining 2 tbsp (25 mL) sugar. Remove 1-1/2 cups (375 mL); cover and refrigerate until serving or for up to 24 hours.

In large bowl, combine ice cream and remaining berry mixture; spoon half into prepared crust. Smooth top and sprinkle with reserved graham crumb mixture and walnuts; drizzle with caramel syrup. Spoon remaining ice cream on top and smooth surface. Cover and freeze for 4 hours or until firm, or for up to 4 days. 

To serve, top cake with strawberries in centre. Slice cake into wedges and drizzle with strawberry sauce.

Tips:  Purée strawberries in blender or food processor. To mash strawberries use a potato masher or large serving fork. Pick only the best ripe strawberries and wash them just before eating.