Sunday, January 9, 2011

Banh Bo Nuong (Vietnamese Honeycomb Cake)

Who knew that Vietnamese Honeycomb Cake (Banh Bo Nuong) would end up being one of the most difficult cakes I've ever tried to make?  My friend gave me a delicious homemade Banh Bo Nuong around Christmas time, and I've been trying to duplicate it ever since.  The more I failed, the more determined I was to get it right.

My first (unsuccessful) attempt used this recipe I found on a blog - I followed the instructions to the letter (used the right kind of baking powder, didn't overbeat the eggs, etc.) - but I ended up with a deflated, mushy, compact gelatinous brick.  It also wasn't sweet enough - blech! - the results went into the trash.  

For attempt #2, I thought, "Maybe the cake doesn't have enough gluten to provide structural support?"  So I substitute cake flour for half of the tapioca flour, increased the sugar, and ended up with something that tasted more like a Pandan pound cake - good, but no honeycombs - and it definitely wasn't Banh Bo Nuong.  

Attempt #3 utilized a combination of tapioca flour, rice flour, and a small amount of cake flour - I was hoping the rice flour would give a chewier texture and also help with the structure of the cake to prevent it from collapsing.  Nope, wrong again!  Cake #3 was good - but still was nothing more than a Pandan pound cake, and still did not resemble Banh Bo Nuong.

Attempt #4 finally gave me results worth posting.  I decreased the amount of coconut cream, increased the sugar, went back to all tapioca flour... plus I increased the oven heat, and implemented chiffon cake strategy when cooling the cake.  Success!  Here is what I learned:

There are several steps that must be strictly adhered to when making this cake:  First, use only SINGLE-acting baking powder.  Most American markets stock only DOUBLE-acting baking powder - which is great for banana bread - but will ruin your honeycomb cake.  You can find little pink packets of Alsa brand (single-acting) baking powder at Asian markets. Or, make your own baking powder by combining cream of tartar and baking soda in a 2:1 ratio.  My successful cakes #4 and #5 both used cream of tartar + baking soda, so I know that it works.

Second, make sure you preheat your cake pan, greasing only the bottom.  Leave the cake pan sides un-greased, to give the cake something to cling to for support.  Angel food cake pans are great for this cake, as the center tube will give added support.  If your cake lacks the honeycombs, it could be that your oven is not hot enough, or could be out of calibration - experiment with baking at 10 degree hotter temperatures until it works.  Once baked, hang the cake upside-down on a rack to cool, if possible.  This will help reduce the likelihood of your cake collapsing when cooling. 

Third, be careful not to beat any air into your batter.  The trapped air will expand in the oven, causing the cake to rise... and the more air that is incorporated, the more the cake will deflate as it cools.  Stir your ingredients slowly - resist the urge to use a beating or whipping motions.

Tapioca starch and tapioca flour are the same thing - use either. You can find tapioca flour at an Asian market, or at a "Whole Foods" type of health food market.  I bought my latest batch of tapioca starch at Sprouts Market, Bob's Red Mill brand.  Coconut cream is thick coconut milk.  You can sometimes find coconut cream for sale in cans, like I did.  Or, buy coconut milk, and do not shake or agitate - open the can, and use the thick layer of cream that has floated to the top of the can.

Banh Bo Nuong:
1/2 c. coconut cream
1 1/4 c. sugar
6 eggs
1 1/4 c. tapioca starch
2 1/2 tsp. single acting baking powder (make your own with 1 3/4 tsp. cream of tartar + 3/4 tsp. baking soda)
1/2 tsp. salt
1/2 - 1 tsp pandan extract
1 tsp. vanilla extract

1.  Preheat a convection oven to 360 degrees (375 degrees in a regular oven).  Grease the bottom (not the sides) of an angel food cake pan with canola oil, and allow the pan to preheat inside the oven.  (You want the pan to be nice and hot when you add the cake batter.)

2.  Sift the tapioca starch, and baking powder.  Do not use double acting baking powder, or this recipe will fail.

3.  In a separate container, stir the eggs until homogenized - you want to avoid beating any air into the eggs.

4.  Mix the coconut cream, sugar, pandan, and vanilla extracts.  Stir until sugar is dissolved.

5.  Stir the eggs into the coconut milk syrup.  Do not beat or overly agitate the mixture.

6.  Pour the wet ingredients on top of the dry ingredients, and mix to combine.  Stop mixing when you still have some lumps - over mixing will ruin this cake.

7.  Pour the batter through a sieve, and using the back of a rubber or silicone spatula, push all of the batter through.  This step will take care of all the lumps, allowing a nice smooth batter, without over mixing.  Sieve the batter 2 more times to ensure a perfectly smooth batter.

8.  Pour the batter into the hot cake pan, and bake for 10 minutes at 360 degrees in a convection oven  (375 degrees in a normal oven).  After 10 minutes, reduce the heat to 305 degrees, and continue baking for 25-30 more minutes.  Test with a wooden toothpick - when the toothpick comes out clean, the cake is ready.

9.  Remove the cake from the oven, and invert onto a wire rack.  Allow to hang upside down to cool for at least 90 minutes.

10.  Remove the cake from the pan when cool, and serve.

Note:  You can also make a round version of this cake by baking in a cast iron dutch oven (oil only the bottom of the pan), at 365 degrees in a convection oven for 10 minutes (or 375 degrees in a regular oven), then another 30-35 minutes at 305 degrees.  Hang upside down for several hours to cool.


  1. i tried the original recipe that you sited and my results were the same. =( Thank you very much for this awesome guide, I can't wait to try this version!

  2. Tried the recipe today- its exactly what I've been looking for. Thank you.

  3. Thank you soo much!!! I've been searching for this recipe for years in English and I am happy to say it turned out great when I made it! I forgot to strain it but little lumps don't hurt haha.
    Thanks so much again!

  4. what size of egg did you use? Some recipes require medium egg so i just wonder. Thank you so much for this recipe. I haven't try out your recipe yet but i'll give it a try when i have time this weekend. yes, i have to agree with you about the other recipe. I tried the play with my food's recipe on this honeycomb cake and yes it doesn't turn out right. But again, thanks a lot for your recipe. :)

  5. I used AA Extra Large eggs (from Costco). Good Luck! ;)

  6. Since this is one of those recipes which uses a fair amount of eggs, is anyone bothered by the eggy smell? I was bothered, and using fresh eggs did not eliminate the problem.

    From all my experiments, I think I've finally found a way to reduce the excessive egg smell in the resulting cake. It involves removing the chalaza (spiral bands of tissue in an egg that connect the yolk to the lining membrane at either end of the shell), and the extra thick portion of the egg whites prior to combining with the other wet ingredients in this recipe.

    Hope this helps.

  7. Results were yummy, but I used the angel cake pan and it did not rise evenly one side much higher than the other. should i use more alsa baking soda? I had to bake mine an additional
    10 mins more with a regular oven.

  8. Thank you so much for sharing this recipe!! My mom's tried countless banh bo nuong recipes but they never turned out quite right. Yours is just perfect! :) We make banh bo nuong for every special occasion and our entire family loves them.

  9. The Tapoica starch has gained high prominence in making sabudana. They are also used on a large scale for the preparation of sweet

    dishes and beverages.

    Tapioca Starch Manufacturers, Vietnam Tapioca Starch Supplier

  10. Thanks for this post! My first attempt collapsed badly. I just tried again and as soon as I saw it start to fall I put it back in to the oven and went on Google. Just took it out again and put it upside down. Fingers crossed it doesn't collapse! I know I did beat it too hard though :(

  11. Hi Mika! Thank you so much for your recipe! The first time I made it, it was successful and beautiful. Then The second time I've made it and the cake was half honeycomb that's glossy and clear, the other half was not glossy more like a birthday cake looking. It still tasted amazing and soft. What did I do wrong? Then the 3rd attempt, I've made 2 cakes, make each cake separately and not doubling the recipe.One cake turned out beautiful and the second one was not transparent but still some honey comb effects. The only time I can think of is maybe I've over cooked it? Thanks!

  12. Thank you for the recipe! Came out perfect. I doubled the recipe and it was the perfect amount for the regular bunt cake pan. I didnt have to flip the cake. It stod tall after cooled down. This one is a keeper

  13. Omg! After 3-4 tries of other recipes this one hands down best tasting!! Thank you! The flavor is exactly what I was expecting from previous attempts but they were too strong! This was the best! Thank u!!

  14. I've made 2 attempts and they both turned flat and gummy. What can i be doing wrong?