Mixed-Berry Icebox Cake

Beat whipping cream, vanilla, and ½ cup sugar with an electric mixer fitted with a whisk attachment on medium-high speed until stiff peaks form, about 2 minutes.

Combine strawberries, raspberries, blackberries, and remaining 2 tablespoons sugar in a large bowl. Mash berries with a fork until very few clumps remain. Let sit until juicy, about 5 minutes. Press berry mixture through a fine-mesh strainer to equal about ¾ cup juice; discard solids or save for another use. Fold berry juice into whipped cream until well blended.

Spread ¼ cup whipped cream mixture in a 6-inch circle in center of a serving plate. Arrange 7 crackers in a circle on top of cream. Place 1 more cracker in center of circle. Spoon ¾ cup whipped cream mixture on top of crackers, spreading to edges of circle. Top with 8 more crackers in same pattern. Top with another ¾ cup whipped cream mixture and 8 more crackers. Spoon ¼ cup jam over third cracker layer. Top jam with another layer of crackers. Repeat layering until you have 11 layers of crackers, spreading jam over every third cracker layer. Spread remaining whipped cream mixture on top and sides of cake.

Refrigerate, uncovered, until firm, about 4 hours. Top with more berries just before serving.