This Vietnamese honeycomb cake or banh bo nuong is one of the most iconic cakes in Vietnamese cuisine. The name comes from the distinct honeycomb structure created by pockets of expanding gas which can be seen when you cut a cross section of the cake. Honeycomb cake is traditionally served warm and is perfect on its own or with a nice cup of hot tea.
This cake comes in a variety of flavours but it is most commonly made with pandan. This is easily my favourite flavour since it gives the cake a vibrant bright green colour and a wonderful fragrance. Steph however, prefers vanilla brown sugar which admittedly is pretty good too! In today’s post I have included both recipes so that you can decide for yourselves which one you enjoy better.
Honeycomb cake is one of those recipes where you only hear how hard it is or how there is a secret ingredient which for some reason no one tell you. So for the longest time, I avoided making it until many years later when I finally grew a pair and gave it a crack. On my first attempt I literally baked a brick. The cake was flat, lifeless and the honeycomb structure was as solid as a block of cheese. Fortunately, my brick laying days are over and the cake looks like how it is in the pictures 99% of the time.
My Tips for Success
As I mentioned above, this recipe does have a few booby traps, so here are my best tips to avoid disappointment!
- Pandan extract comes in many varieties which all differ in quality. I use the Koepoe Koepoe Pandan extract / paste which is a thick, viscous dark green syrup. Avoid buying anything that looks very diluted (light green) and thin.
- Use scissors to cut the yolks up in the bowl. This is to avoid putting too much air in the cake mixture.
- When whisking the mixture, keep it slow and steady with the whisk always touching the bottom of the mixing bowl.
- Let the cake cool upside down to avoid it collapsing on itself when it is hot.
- Ideally don’t use a non-stick cake tin since you want the cake to stick onto the sides of the tin. This will keep the cake in the tin when letting it cool upside down.
- Do not grease the sides of the tin for reasons stated above.
- All ovens are different. If the cake looks like its going to burn on the top at any point, turn down the heat to 170 C / 338 F or lower if necessary.
- And with all things that are loaded with booby traps, take your time. Don’t rush it.
If you are thinking of making this for the first time or have been disappointed with other recipes then this one is for you. I have made the recipe as simple as possible and included all my tips to avoid failure. I promise if you give it a go, there will be beautiful honeycomb cake to enjoy with family and friends or…. for yourself!
Scruff & Steph
Vietnamese Honeycomb Cake – Banh Bo Nuong
- 1/2 tsp canola oil (for greasing the tin)
- 1 cup coconut cream
- 1/4 tsp salt
- 1/2 tsp pandan extract / vanilla extract (available at Asian groceries) (Note 1)
- 150 gm white caster sugar / brown sugar (Note 1)
- 1 tbsp canola oil (for the cake mixture)
- 5 large eggs, at room temperature
- 160 gm tapioca starch (available at Asian groceries)
- 10 gm rice flour (available at Asian groceries)
- 2 tsp cream of tartar
- 1 tsp bicarb soda
- Preheat the oven to 180 C / 356 F fan-forced.
- Grease the bottom of a 20 cm / 8 inch round cake tin with the 1/2 tsp of oil and leave it in the oven to heat up.
- In a bowl, add the coconut cream and salt. If making the pandan version then add pandan extract and white caster sugar to the mixture. If making the brown sugar version then add the vanilla extract and brown sugar to the mixture.Put into the microwave for 1 minute, then mix until combined. Add the tbsp of canola oil and set aside.
- Crack the eggs into a large mixing bowl. With a pair of scissors, cut the egg yolks into small pieces, then add the coconut mixture.
- Sift half of the tapioca starch and rice flour into the egg mixture and gently whisk while keeping the whisk touching the bottom of the bowl at all times. After about a minute, add the remaining tapioca starch and flour and continue whisking for another minute.
- Sift the cream of tartar and bicarb soda into the mixture. Mix for roughly 30 seconds.
- Take the cake tin out of the oven and place it on a heat-proof surface..
- Press the cake mixture through a sieve and into the hot cake tin. Grab your oven mitts or a thick tea towel, and drop the cake tin from a height of roughly 2 cm onto your work surface a few times to get the air bubbles out.
- Put the cake into the oven and bake for 40 minutes.
- Set up a cooling station by placing a cooling rack on a couple of mugs, or something else that will give the cooling rack some height. See picture above to see what I mean. This is to allow plenty of air to circulate under the cake to reduce any condensation as it cools upside down.
- After 40 minutes, take the cake out of the oven and immediately rest it upside down on the cooling station.
- After about 45 minutes of cooling, or once the cake feels lukewarm, remove from the tin and serve.
- Use pandan extract or paste for the pandan version and vanilla extract for the brown sugar version. Please refer to my tips for which pandan extract to buy.