Assemble the Shell

Line the bottom of a 9-inch springform pan with a round of parchment paper. Stand the ladyfingers upright around the inside edge of the pan, rounded side out, with the sugared sides facing out and fitting snugly. Trim a few as needed to fit the base, then arrange them in a tight layer on the bottom of the pan.

Make the Mousse

Puree the strawberries, granulated sugar, and lemon juice in a blender or food processor until smooth. You should have about 1 1/2 cups of puree.

Sprinkle the gelatin over the cold water in a small bowl and let it sit for 5 minutes, until spongy.

Warm 1/2 cup of the puree in a small saucepan over low heat until hot but not boiling. Remove from the heat, add the gelatin mixture, and stir until completely dissolved.

Stir the warm gelatin mixture into the remaining puree. Refrigerate for 20 to 30 minutes, stirring occasionally, until cool and slightly thickened but not set.

In a chilled bowl, whip the cream, powdered sugar, and vanilla to medium-stiff peaks.

Fold about one-third of the whipped cream into the strawberry mixture to lighten it. Gently fold in the remaining whipped cream until no streaks remain.

Spoon the mousse into the ladyfinger-lined pan and smooth the top. Cover and refrigerate for at least 6 hours, or overnight, until fully set.

Top and Serve

For the glaze, warm the jelly and water in a small saucepan or microwave until pourable. Cool slightly.

Run a thin knife around the edge, release the springform, and remove the parchment base if desired. Slice with a warm, clean knife.