Preheat your oven to 350°F (175°C) and line a 9-inch square baking pan with parchment paper.

Cream together the unsalted butter and granulated sugar until light and fluffy. Mix in egg yolks, flour, and baking powder until cohesive. Press into prepared pan.

Spread a layer of raspberry jam over the shortbread base, ensuring even coverage.

In a double boiler, combine egg whites and sugar, whisking until it reaches 160°F (71°C). Whip until glossy peaks form, then fold in shredded coconut.

Spread the coconut meringue over the jam layer and bake for 30 minutes or until light golden.

Allow the cake to cool completely before lifting it from the pan and slicing into squares.