Kue Lapis — layered Indonesian steamed rice-flour cake

i. Origin & history

Kue lapis belongs to the kue tradition of Indonesia — the market snacks and sweets that occupy a category of their own, eaten between meals and at celebrations. It is made across the archipelago and has close equivalents throughout the region: kuih lapis in Malaysia and Singapore, and banh da lon in Vietnam, which is built on the same principle with the same ingredients.

The technique of building a cake from separately cooked thin layers is old and is shared across the region, and it is a technique born of equipment as much as taste: a steamer is a far more common household tool than an oven across much of Southeast Asia, and steaming thin layers in sequence is how you make something cake-like without baking.

The naming problem is worth settling early, because it trips up almost everyone. Kue lapis, plain, normally means this steamed rice-flour cake. Kue lapis legit — also called spekkoek — is a completely different and much richer thing: a baked cake of butter, egg yolks and heavy spicing, built up by grilling one thin layer of batter at a time under a broiler, often with thirty layers or more, and strongly associated with the Dutch colonial period. They share only the word 'layer'.

Colour is a large part of the appeal, and traditionally it came from natural sources — pandan for green, butterfly pea flower for blue, palm sugar for brown. Modern versions frequently use food colouring, and the bright pink-and-white striped kue lapis is now the default image of it.

ii. Why each layer is steamed separately

The layers exist because they are cooked one at a time. There is no folding, no piping and no assembly — a thin ladleful of batter goes into the hot steamer, sets, and the next colour goes straight on top of it.

This works because the batter is starch-based rather than egg-based. Rice flour and tapioca starch gelatinise when heated in liquid, turning from a thin white suspension into a translucent, springy gel. A thin layer sets in five to eight minutes; the surface remains just tacky enough that the next layer bonds to it rather than sliding off.

The proportion of tapioca starch to rice flour is what controls the texture, and it is the main variable between recipes. More tapioca gives a chewier, springier, more translucent cake; more rice flour gives a softer, more tender, more opaque one. Neither is wrong, but a cake made with rice flour alone will be crumbly and will not peel, and one made with tapioca alone will be unpleasantly rubbery.

Two failures dominate. Layers that separate when cut mean each layer was steamed too long and set too dry to bond with the next — the surface should still be slightly tacky when the next ladle goes on. Layers that blur together mean the opposite: the previous layer had not set enough before the next was added.

The final complication is that the batter separates as it stands. Rice flour and tapioca settle to the bottom of the bowl within minutes, so the batter must be stirred before every single ladleful or the later layers will be thin and watery while the early ones are dense.

iii. Ingredients

Makes 16 servings · scroll the side panel to adjust

• 200 g rice flour
• 100 g tapioca starch
• 250 g sugar
• 600 ml thick coconut milk
• ½ tsp salt
• 2 pandan leaves, knotted
• 1 tsp red food colour
• 1 tsp green food colour or pandan paste

The ratio of rice flour to tapioca starch is the main lever: roughly equal parts gives a good balance of springiness and tenderness. Use full-fat coconut milk; it is most of the flavour, and light coconut milk gives a thin, characterless cake. A pinch of salt is essential — it is what stops the cake reading as flatly sweet, and its absence is noticeable. For colour, pandan extract gives green and aroma together, butterfly pea flower gives a natural blue, and palm sugar gives brown; food colouring is entirely standard in modern practice. Grease the tin with oil, not butter, which would separate in the steamer.

iv. Method

1. Simmer 200 ml of the coconut milk with the pandan leaves and salt for 5 minutes; cool. Combine remaining coconut milk with sugar; stir to dissolve.
2. Whisk both flours into the cooled pandan coconut milk, then strain into the sweetened coconut milk. The batter should be smooth, thin, and pourable.
3. Divide into two bowls. Tint one pink, one green.
4. Lightly oil a 20 cm square steamer tin. Steam empty for 5 minutes to heat. Pour in a thin ladle (about 5 mm) of pink batter; steam 5 minutes until set. Pour over a layer of green; steam 5 minutes. Continue alternating until you have at least 8 layers.
5. Steam the finished cake an extra 10 minutes. Cool completely (4 hours minimum, ideally overnight) before turning out and cutting into diamonds. Peel layers apart to eat — that is half the pleasure.

v. Tips & common mistakes

• Stir the batter before every ladleful. The starches settle within a couple of minutes. If you do not re-stir, your early layers will be dense and your late ones watery — this is the most common cause of an uneven cake.
• Steam each layer until just set, not dry. Five to eight minutes, until the surface is no longer liquid but still slightly tacky. Over-steamed layers set too dry to bond, and the finished cake will fall apart into separate sheets when you cut it.
• Keep the steamer at a full, steady boil. The heat has to be consistent or the layers set at different rates and the cake becomes uneven. Top up with boiling water as needed.
• Wrap the steamer lid in a cloth. Condensation dripping onto the surface pits the layers and makes them patchy. A cloth tied around the lid catches it — this is standard practice for all steamed kue.
• Keep the layers thin and equal. Use the same measure — a small ladle or a quarter-cup — every time. Thick layers do not set through properly, and unequal ones spoil the whole point of the cake.
• Cool completely before cutting, and oil the knife. Several hours, ideally. Cut warm, it drags and tears; cut cold with an oiled blade, it gives clean edges and distinct stripes.

vi. Variations

Kue lapis beras is the standard steamed rice-flour version. Kue lapis sagu uses sago or more tapioca for a chewier cake. Kue lapis legit (spekkoek) is the unrelated baked, spiced, butter-and-egg-yolk cake of Dutch-Indonesian tradition. Kuih lapis is the Malaysian and Singaporean name for essentially the same steamed cake, and bánh da lợn is the Vietnamese equivalent, usually pandan and mung bean. Colour and flavour variations include pandan, palm sugar, butterfly pea, durian and chocolate.

vii. Serving & storage

Kue lapis is served at room temperature, cut into diamonds or squares, as part of a spread of kue rather than as a plated dessert. The traditional way to eat it is to peel the layers apart one at a time with your fingers, which is both a genuine pleasure and the reason the layer bonding matters so much. Tea or black coffee is the usual accompaniment.

It is best on the day it is made and should be kept at room temperature under a cover. Do not refrigerate it — rice flour and tapioca retrograde in the cold, and the cake goes hard, dry and grainy within hours, which is the single most common way people ruin a good kue lapis. If you must chill it, steam the slices briefly to bring the texture back before serving. It does not freeze well for the same reason.

ix. More from Indonesian & Malaysian

• Klepon — palm-sugar rice balls
• Dodol — palm-sugar candy
• Sapin-Sapin — Filipino layered rice cake
• Khanom Chan — Thai layered rice cake
• Banh Da Lon — Vietnamese layered tapioca cake
• Kue Putu — steamed bamboo cakes