Prepare the Crust: Preheat oven to 350°F (175°C). Line the sides of a 9-inch springform pan with parchment paper.

In a medium bowl, combine shortbread crumbs, sugar, and melted butter. Press mixture into the bottom of the prepared pan.

Bake crust for 10 minutes. Remove from oven and set aside to cool.

Make the White Chocolate Ganache: In a medium bowl, place white chocolate chips.

In a separate saucepan, heat butter, heavy cream, and lemon zest until boiling. Pour over white chocolate chips. Cover and let sit for 5 minutes.

Whisk until smooth. If needed, microwave in 10-second intervals, stirring in between, until fully melted.

Spread ganache evenly over cooled crust. Refrigerate until firm.

Prepare the Lemon Curd: In a double boiler, combine lemon juice, lemon zest, sugar, and egg yolks. Whisk constantly until mixture reaches 160°F (71°C).

Remove from heat and stir in butter until melted. Refrigerate until thick and cool.

Make the Lemon Mousse: Sprinkle gelatin over cold water and let bloom for 5 minutes.

Heat gelatin mixture until dissolved. Let cool to room temperature.

In a large bowl, whip heavy cream and powdered sugar until stiff peaks form.

Gradually add cooled gelatin to whipped cream.

Fold in lemon curd until well combined.

Spread lemon mousse evenly over white chocolate ganache. Refrigerate until set.

Prepare the Blueberry Mousse: Puree blueberries and strain to remove pulp.

Sprinkle gelatin over blueberry puree and let bloom for 5 minutes.

Heat gelatin mixture until dissolved. Let cool to room temperature.

In a large bowl, whip heavy cream and powdered sugar until stiff peaks form.

Gradually add cooled gelatin to whipped cream.

Fold in blueberry puree until well combined.

Spread blueberry mousse evenly over lemon mousse. Refrigerate until firm, about 5–6 hours.

Serve: Remove sides of springform pan. Garnish with fresh blueberries and lemon slices.