Bánh da lợn or bánh da heo (literally “pig skin cake”) is a Vietnamese steamed layer cake made from tapioca starch, rice flour, mashed mung beans, taro, or durian, coconut milk and/or water, and sugar. It is sweet and gelatinous in texture, with thin (approximately 1 cm) colored layers alternating with layers of mung bean, durian, or taro filling.

Typical versions of bánh da lợn may feature the following ingredients:

• Pandan leaf (for green color) with mung bean paste filling
• Pandan leaf (for green color) with durian filling
• Lá cẩm (leaf of the magenta plant, Peristrophe roxburghiana; imparts a purple color when boiled) with mashed taro filling

In modern cooking, artificial food coloring is sometimes used in place of the vegetable coloring.

While The Astronomer was working on his tenth hour of continuous sleep this morning, I explored the wonders of District 4. I picked up fruits galore and bánh da lợn (1,000 VND). I’ve seen this sticky number sold all around town, but was always turned off by its bright green, food coloring induced glow. The ones I picked up this morning were naturally green due to pandan leaves rather than science, and filled with mung bean paste. According to the vendor, the bánh da lợn came from the city of My Tho in the Mekong Delta and are rarely sold in Saigon. It’s my lucky day.