To start, preheat your oven to 180℃ bake, then line a square 20cm baking tin with grease-proof paper and set aside.
To make the dough, add the butter and sugar to a medium sized bowl and beat with a hand-held mixer until combined and smooth. Finally, beat in the egg and vanilla until incorporated. Fold in the flour and coconut with a spoon until a dough comes together, then set aside.
To make the filling, chop up the pineapple pieces and add them to a bowl (draining juice out). Mix through the sugar and cornflour and set aside.
To assemble, press ⅔ of the dough into the base of prepared baking tin. Pour over the pineapple mixture, then crumble the remaining ⅓ of dough over top. Feel free to sprinkle a little more dessicated coconut over top to give a little more texture.
Bake for about 45 minutes, or until golden and baked through. NOTE: After 30 minutes or so, you may want to cover with tin foil if the top of the shortcake begins to darken too much.