Preheat oven to 170°C (340°F). Line an 8-inch round cake tin with parchment paper.

Sift flour, baking powder, and salt together. Set aside.

In a large bowl, beat eggs and sugar until thick, pale, and tripled in volume (about 8–10 minutes).

Mix coconut milk, oil, vanilla, and coconut extract in a small bowl.

Gently fold the flour mixture into the egg mixture in two batches.

Add the liquid ingredients slowly, folding carefully to maintain the volume.

Pour into tin and bake for 25–30 minutes or until a toothpick comes out clean.

Let cool completely before slicing.

Combine pineapple juice, sugar, and rum (if using). Stir until sugar dissolves.

Beat chilled cream with powdered sugar until soft peaks form.

Fold in desiccated coconut.

Slice the sponge into two layers.

Brush each layer generously with the soaking syrup.

Spread whipped coconut cream and add crushed pineapple between layers.

Frost the outside with the remaining cream.

Decorate with pineapple chunks and toasted coconut if desired.