Puree the strawberries and granulated sugar in a blender or food processor until pourable, but still slightly chunky.
Have ready a 2-quart dish.
In the bowl of a stand mixer fitted with the whisk attachment, whisk the cream on medium to medium-high speed until the cream begins to thicken, about 2 to 3 minutes. Add the confectioners’ sugar and the remaining vanilla, and whisk until stiff peaks form. With a rubber spatula, gently fold the strawberries into the cream.
Using a small offset spatula or the back of a spoon, spread a layer of cream on the bottom of the pan. Cover as much of the cream as possible with a layer of vanilla wafers, filling any gaps with broken wafers (breaking them yourself, if necessary). The pieces should touch. The goal is a solid layer of cookies.
Continue layering whipped cream and cookies until you run out or reach the top of the pan. Spread the top of the cake with whipped cream and gently cover it with plastic wrap. Refrigerate the cake for 6 to 8 hours, or preferably overnight.
Remove the cake from the refrigerator prior to serving and peel off the plastic wrap. Sprinkle the top of the cake with red sanding sugar.
Serve directly from the pan. The cake will keep, tightly covered with plastic wrap in the refrigerator for up to 3 days.