How to Make It
Beat whipping cream, jam, and vanilla with a heavy-duty stand mixer fitted with a whisk attachment on medium-low speed until fully combined, about 30 seconds. Increase speed to medium-high; beat until mixture begins to thicken, about 1 minute. Increase speed to high; beat until very thick, 1 to 1 1/2 minutes.
Place a 12-inch paper doily (or a 12-inch parchment paper circle) on a cake plate. Spread a thin layer (about 1/4 cup) whipped cream mixture in a circle on doily, leaving a 2-inch border. Top with 6 wafer cookies arranged in a circle with edges touching; place 1 additional cookie in middle of cookie circle. Spread with about 1/2 cup whipped cream mixture, leaving a 1/4- to 1/2-inch cookie border.
Add a second cookie circle layer with 6 cookies placed in between cookies of the first layer; place 1 additional cookie in center of second cookie circle. Spread with about 1/2 cup whipped cream mixture, leaving a 1/4- to 1/2-inch cookie border. Working quickly (so that cake doesn’t start to collapse), repeat layers until no cookies remain (about 8 additional layers), ending with a cookie layer. Spoon desired amount of remaining whipped cream mixture on top. Chill, uncovered, at least 5 hours or up to 8 hours.
Decorate cake with fresh strawberries, and serve. Leftovers may be stored, covered, in refrigerator up to 2 days.