Bake the walnuts in the oven (350°F/180°C) or cook over the stovetop until golden brown and toasty, about 7-10 minutes. Set aside. *Note 2
Prepare the jujubes by cutting around the pit with a knife or scissors. Remove the pits.
In a blender or food processor, blend the jujubes with 240 grams of water until it is a smooth, thick paste. Add more water as needed to reach that consistency. *Note 3
Pour the blended red dates into a large non-stick pan. Stir in maltose and oil.
Turn on the heat to medium-low/medium and cook until the mixture thickens, about 25 minutes. The stove should be hot enough that the mixture bubbles once or twice when not stirred. Stir the mixture with a silicone spatula periodically to prevent the bottom from burning/sticking.
Mix tapioca starch with water in a small bowl until no lumps of starch remain.
Pour the tapioca starch slurry into the mixture and immediately stir to combine. Continue cooking, stirring periodically, until the mixture thickens into a dough-like consistency and no longer sticks to your pan/spatula. This can take up to another 20 minutes. ** Note 4
Fold the toasted walnuts into the jujube mixture.
Transfer the dough onto a large piece of parchment paper or a silicone mat. Fold the edges of the paper/mat over the candy to form it into a rectangle. Use a rolling pin to flatten the candy to about a 1/2-inch (~1.25 cm) thick.
Once the candy has cooled to room temperature, place it into the refrigerator to harden, roughly 2 hours.
Remove the paper/mat and cut the candy with an oiled knife into 1/2 x 2-inch (1.25 x 5 cm) pieces or your desired shape.
Optional but recommended: Use parchment paper/wax paper/edible glutinous rice paper wrappers to wrap the candies to prevent them from sticking to each other in storage. Store in the refrigerator to prevent the candy from softening too much.