Pour about 2 to 3 cups of the jelly into a small dish. Let the jelly set slightly before placing it in the fridge to set completely.
Spoon half of the remaining black coffee jelly solution in the pot into the prepared mini jelly molds. Let the jelly set.
While waiting for the black jelly layer to set, prepare the milk coffee jelly. To do this, add condensed milk to the remaining jelly solution in the pot. Mix well.
Also, prepare the black coffee jelly cubes. Remove the dish of black jelly placed in the fridge earlier. It should have set completely by now, given that it is a shallow layer of jelly. Cut the jelly into small cubes of about 1cm sizes. You can cut the jelly directly in the dish or you can also turn it out onto a board and then cut it.
Remove the jelly molds from the fridge. Check that the top of the black jelly is firm by pressing it lightly. So long as the top of the jelly is firm to the touch (the bottom can still be wobbly, that is fine), it is ready for the next layer of jelly.
Gently spoon the milk coffee jelly onto the black jelly layer.
Add a few of the cut black jelly cubes into each of the jelly molds. You will see the jelly cubes float to the surface of the milk coffee layer. At this stage, not all the jelly cubes will be used up. Reserve the remaining for the topping.
Return the jelly in the molds to the fridge to set completely.
While waiting for the jelly to set, prepare the jelly topping.
To make the topping, cut the remaining black jelly cubes into smaller squares.
Chill in the fridge while waiting for the jelly in the molds is set.
Spoon some of the jelly toppings onto each mini coffee jelly in the molds before serving.