Sift almond flour, icing sugar, and ground pistachios together twice.

Whisk egg whites until soft peaks form, then gradually add caster sugar until stiff and glossy.

Gently fold the dry ingredients into the meringue until the batter falls off the spatula in a 'ribbon'.

Pipe small circles onto a baking sheet lined with a silicone mat.

Tap the tray to release air bubbles and let sit for 30-60 minutes until a skin forms.

Bake at 300°F (150°C) for 14-16 minutes.

For the filling, melt white chocolate with cream and stir in pistachio paste. Chill until firm.

Pipe a ring of pistachio ganache on a shell, fill the center with raspberry jam, and top with another shell.