Preheat oven to 100°C. Grease, then line 3 large oven trays with baking paper. Put almond meal, icing sugar and salt in the bowl of a food processor, then process. Sift into a large bowl to remove any large, coarse pieces.
Beat eggwhites, caster sugar and coconut essence in the small bowl of an electric mixer for 5 minutes or until mixture reaches the consistency of softly whipped cream.
Add to sifted dry ingredients and stir until combined. Fit a large piping bag with a 1cm plain nozzle and fill with mixture. Pipe 2.5cm rounds onto prepared trays, 3cm apart.
Bake for 45-50 minutes or until crisp on top, turning trays once. Macarons are ready if they come off tray without sticking to base; if not, bake a little longer. Cool on trays.
To make frosting, sift icing sugar into a medium-sized bowl. Add butter and passionfruit pulp. Beat using an electric beater until frosting becomes thick and spreadable. If frosting is too dry, add a teaspoon of water. Gently spread a small amount of frosting onto the flat side of half of the macarons. Top with remaining halves. Serve.