Chill the coconut milk overnight, then scoop the solidified cream into a bowl. Beat with powdered sugar and vanilla until light peaks form. Chill until ready to use.

Preheat oven to 350°F (175°C). Line three 6-inch cake pans with parchment. Whip egg whites and cream of tartar until foamy. Gradually add 100g sugar, beating until stiff peaks form.

In another bowl, whisk egg yolks and remaining sugar until pale. Add milk, oil, vanilla, pandan extract, and gel coloring. Mix until combined.

Sift flour and baking powder into the wet mixture and fold gently. Fold in a third of the meringue, then the rest until no streaks remain.

Divide batter among pans (about 200g each). Bake for 23-25 minutes or until a toothpick comes out clean. Cool upside down on a wire rack.

Layer cooled cakes with frosting. Apply a crumb coat, then a final layer of frosting for an elegant finish.

Decorate with coconut flakes. Chill for 1-2 hours before serving to allow flavors to meld.