Prepare the coconut and mung beans:
- Choose a mature coconut (the kind used for drinking, not dried coconut for extracting coconut milk). After using the water, split the coconut and use a grater to shred 100 grams of coconut meat.
- Rinse the mung beans and soak them in warm water for 1 hour until they soften.

Make the mung bean and coconut filling:
- Steam the mung beans until cooked, then mix in salt, sugar, and shredded coconut.
- Steam the mixture for another 5 minutes so the sugar dissolves and the coconut softens.

Prepare beet juice:
Wash and trim the beet, then juice it to get pure beet juice.

Mix the batter:
- Combine 1 cup (260 grams) water with 1/4 cup (60 grams) beet juice.
- In a bowl, mix tapioca starch, rice flour, salt, and sugar. Add the diluted beet juice and vegetable oil, then stir until smooth. Let the batter rest for 30 minutes.

Cook and shape the bánh cuốn:
- Use a nonstick pan to cook the crepes, or steam them on a plate.
- Place the cooked crepe on a silicone mat to prevent sticking, add the filling, fold in the sides, and roll tightly. Repeat until all the batter is used.

Finished dish:
- Sweet bánh cuốn has a thin, chewy wrapper and a rich, sweet mung bean and coconut filling. The rolls look beautiful and taste great, especially when served with crushed sesame salt. (The beet is used for color and does not give a strong flavor.)