- In a saucepan, bring 60 ml (1/4 cup) of water with the sugar and lemon juice to a boil, stirring until the sugar has dissolved. Add the remaining water.
- In a saucepan, sprinkle the gelatin over the water and let bloom for 5 minutes. Add 125 ml (1/2 cup) of strawberry sauce, 180 ml (3/4 cup) of sugar and cook, stirring constantly, until the gelatin has dissolved. Let cool and stir in the remaining sauce.
- In a bowl, whip the cream with the remaining sugar and the vanilla until stiff peaks form. Gently fold in the strawberry mixture, using a spatula. Set aside.
- Line the bottom of a 20-cm (8-inch) springform pan with parchment paper. Line the edge with a strip of parchment paper.
- Cut each cookie into 7-cm (2 ¾-inch) long pieces. The smaller pieces will be used to line the bottom of the pan. Quickly dip the smaller cookie pieces in the syrup and cover the bottom of the pan. Repeat the soaking with the long cookie pieces and place them upright, flat side inward, along the inner walls of the pan. Fill with the strawberry mixture and garnish with the strawberries, pressing them lightly in the filling. Gently cover the pan with plastic wrap and refrigerate for 8 hours or overnight.
For about 375 ml (1 1/2 cups) of strawberry sauce, just puree about 1-litre (4 cups) of strawberries in the food processor until smooth and strain through a sieve.