To explain my background, my parents are both Indonesian-born, but their parents come from south China. My parents grew up in Indonesia and later on, Singapore. A lot of Indonesian culture is influenced by the Dutch because Indonesia was occupied by the Dutch (the Dutch East India Company, or VOC) for about 200 years. Indonesian cuisine has definitely been affected by the Dutch, and vice-versa.
Now, I don’t think she put any rum in hers, and sharing her exact recipe would be fruitless because she uses products that are available exclusively in Indonesia, but I found a very close recipe online that also doesn’t use rum. If you do choose to use rum, I recommend a dark or spiced rum. This recipe is a great way to use up any stale leftover cake.
Leftover chocolate cake/cake scraps
Mini pastry cups, if desired
Dissolve the cocoa powder in the hot water and stir till you get a thin consistency. Pour the mixture a little at a time into the bowl of cake scraps. Mix well using your fingers. The mixture should be sticky and easily formed into balls. Once you are satisfied with the consistency, you can shape the mixture into balls of about 1 inch in diameter.
For a final touch, roll each ball in sprinkles and place in pastry cups, if you desire.