Preheat your oven to 180°C (350°F) and prepare a 9-inch square baking pan lined with parchment paper.

Cream together 125g of softened unsalted butter and 125g of caster sugar until light and fluffy, about 3-5 minutes. Add in 3 egg yolks and mix well. Gradually sift in 250g of all-purpose flour and a pinch of salt, mixing until the dough becomes slightly crumbly.

Spread a generous layer of raspberry jam evenly over the shortbread base. Aim for about 200g of jam for adequate flavor.

In a double boiler, combine 5 egg whites and 150g of caster sugar, whisking gently until warm. Transfer to a stand mixer and whip until stiff peaks form.

Gently fold in 100g of shredded coconut into the meringue.

Spread the coconut meringue over the raspberry jam layer and smooth it evenly.

Bake in the preheated oven for about 30 minutes until the meringue is lightly golden.

Let the cake cool completely in the pan, then lift out using the parchment paper and slice into squares for serving.