Place the gula melaka and water in a pot or saucepan set over low heat, and let it slowly simmer for 5-10 minutes, until the sugar has completely melted. Take it off the hear, and let cool to room temperature, then mix it together with the coconut milk.

Sift together the flour, salt, baking powder, and baking soda, making sure there are no lumps for a smooth batter later on.

Add the butter and sugar to the bowl of a stand mixer, and beat it on medium speed with a paddle attachment for 2-3 minutes, until the butter lightens in colour and becomes fluffy. Then, add in the eggs one at a time, mixing the batter until each egg is fully incorporated before adding the next. Next, add in the sifted dry ingredients, as well as the gula melaka-coconut milk liquid, in 2-3 incorporations, starting and ending with the dry ingredients (i.e. dry ingredients -> liquid -> dry ingredients -> liquid -> dry ingredients), mixing the batter briefly in between each addition. Finally, add in the rum-soaked longan, and give it a final mix, making sure no streaks of flour remain but also careful not to overmix the batter.

Heat the oven to 180°C. Pour the batter into a greased bundt cake mould (or a line caked tin), and bake the cake for 55-60 minutes, or until a cake tester poked into the centre of the cake comes out clean.

When the cake is done, remove it from the oven and let it cool in the mould for 15 minutes. Meanwhile, you can prep the icing and garnishes! For the icing, mix the powdered sugar, gula melaka, and milk together in a small bowl, and stir it until it comes together into a smooth paste. The rest of the garnishes are pretty self-explanatory, but if you want more gula melaka to drizzle on top, melt some gula melaka in a saucepan. If you want to have some whipped cream to add some levity to the cake, this is a good time to whip it up too.

When the cake is cool, flip it out from the mould or cake tin, and drizzle the icing on top of the cake, letting it gently drip down the sides and crevices of the cake. The, slice the cake up into 8-12 equal slices (or maybe one unequally large slice for yourself), and serve it alongside some shaved gula melaka, gula melaka sauce, gula melaka whipped cream, and all other forms of gula melaka your mind can conjure up!