Bánh da lợn: steamed layer cake

Bánh da lợn is a Vietnamese steamed layer cake made from tapioca starch, coconut milk and sugar, with alternating green pandan layers and yellow mung bean layers. It's chewy, bouncy and lightly sweet, and you make it by steaming one thin layer at a time.

What the name means

Bánh means cake, and da lợn means "pig skin." There's no pork in it. The name refers to the cake's springy, slightly glossy texture. You'll also hear it called bánh da heo in the South, since heo is the Southern word for pig. It's especially associated with Southern Vietnam.

Say it roughly "bahn zah luhn" in the North or "bahn yah luhn" in the South, with a rising tone on bánh, a level tone on da and a low, heavy tone on lợn.

What you need

This makes one 8-inch (20 cm) round or square cake.

Mung bean batter

• 1/2 cup (100 g) peeled split mung beans, soaked 3 to 4 hours
• 1 cup (240 ml) coconut milk
• 1/2 cup (100 g) sugar
• 3/4 cup (90 g) tapioca starch
• 2 tablespoons rice flour
• 1/4 teaspoon salt

Pandan batter

• 1 cup (240 ml) coconut milk
• 1/2 cup (120 ml) pandan juice (from about 10 pandan leaves blended with water and strained) or 1/2 teaspoon pandan extract plus water
• 1/2 cup (100 g) sugar
• 3/4 cup (90 g) tapioca starch
• 2 tablespoons rice flour
• 1/4 teaspoon salt

You'll also need a steamer large enough for your pan and a little oil for greasing.

How to make it

• 1. Drain the soaked mung beans and steam them for about 20 minutes, until soft enough to crush between your fingers.
• 2. Blend the warm mung beans with 1 cup of coconut milk and the sugar until completely smooth. Let it cool slightly.
• 3. Whisk in the tapioca starch, rice flour and salt. Strain the batter through a fine sieve for a silky texture.
• 4. For the pandan batter, whisk together the coconut milk, pandan juice, sugar, tapioca starch, rice flour and salt until smooth. Strain it too.
• 5. Grease your pan lightly and set it in the steamer over boiling water. Let the empty pan heat for 2 to 3 minutes.
• 6. Pour in a thin layer of pandan batter, about 1/3 cup (80 ml), and tilt to spread. Cover and steam 5 to 6 minutes, until the layer turns translucent and set.

Then build the layers:

• 7. Stir each batter before every pour, since the starch settles quickly.
• 8. Add a thin layer of mung bean batter on top and steam for 5 to 6 minutes.
• 9. Keep alternating pandan and mung bean layers until both batters are used. Finish with a pandan layer for a pretty top.
• 10. After the final layer, steam an extra 10 minutes to cook everything through.
• 11. Let the cake cool completely, at least 3 to 4 hours, before cutting. Warm bánh da lợn is too sticky to slice cleanly.

Tips for clean layers

• Wipe the steamer lid. Condensation dripping onto the cake leaves dents. Wrap the lid in a kitchen towel to catch drips.
• Keep the water at a steady boil. Weak steam gives gummy layers.
• Use the same amount each time. A measuring cup keeps layers even.
• Cut with an oiled knife or plastic wrap. Many cooks slice it with a piece of thread or by pressing a plastic knife straight down.

Texture and flavor

The finished cake should be chewy and springy, a bit like a firm gummy, with a gentle coconut richness. The pandan layers taste grassy and vanilla-like, while the mung bean layers are mellow and nutty. It isn't very sweet compared with many Western cakes.

Some versions swap in other flavors: durian, taro, or purple layers made with butterfly pea flower or ube. The method stays the same.

Storing it

Wrap the cake tightly and keep it at room temperature for up to a day. In the fridge it firms up and loses some chewiness; let it come back to room temperature, or steam it briefly for a minute or two, before eating.

Allergens and swaps

Bánh da lợn is naturally gluten-free, as tapioca starch and rice flour contain no wheat, but check labels if you need certainty. It contains coconut, and mung beans are a legume. There are no peanuts, dairy or eggs in this version.

Where it fits

You'll find bánh da lợn in Vietnamese bakeries and markets, often cut into neat diamonds or squares beside other sweets. For more ideas, see Vietnamese desserts to know and try and easy Vietnamese desserts to make at home.

The most important step is patience: let the cake cool fully before slicing, and the layers will show off beautifully.