How to Substitute Almond Flour with Macadamia Flour in Keto Brioche Cake

[Hvitlys]

Hi! I'm trying to bake a keto brioche-type cake that has the shape of a big "donught" and need help after some unsuccessful experiments. It has to be:
- yeast-free
- keto
- without almond flour

I would like to make it with macadamia "flour" instead of almond flour. I tried making the flour myself, since it's not possible to order macadamia flour where I live, but it obviously didn't come out as flour, since macadamia is much fatter than almonds. It wasn't a nut butter either, though.
The dough came out much wetter / fattier, so I added almost 2 tbsp psyllium and let it rest for the psyllium to absorb some of the flour. It wasn't enough to get the right kind of dough (drier), though, so the cake came out flat and oily.
Store-bought macadamia flour is defatted, so I guess I could sub it in this recipe without major problems, but as I said, I can't oder this flour from where I live, unfortunately!

The original recipe I tried to adapt is this one (converted from metric units):
- 4.4 oz cream cheese
- 2.1 oz butter
- 1 tbsp erythritol
- 3 eggs
- 1 tbsp brandy
- 1/4 tsp salt
- 1/2 tsp powdered anise
- 7.4 oz almond flour
- 0.7 oz coconut flour
- 1/2 tsp baking soda
- 2 tbsp lemon juice

First, you cream the cheese with the butter and then the erythritol. Next, you add the eggs and brandy and whisk. Then you add all the dry ingredients and mix with a spatula. Finally, add the lemon juice (I would add it earlier with the wet ingredients, but this cake needs decoration and I'm trying not to let too long a time pass from activating the baking soda, until the cake goes in the oven). Bake at 375 °F, 45 minutes.

I wanted to replace the dairy too, but I didn’t manage and not going to for now (I’m just using non-cow dairy), apparently it’s what makes this cake rise and be fluffy without wheat, so at least the cream cheese (creamed with the butter and then the erythritol) is fundamental for this recipe.

—If I replace almond flour with the same amount of homemade macadamia "flour", how would you adjust the recipe? Since this has to be like a brioche (fluffy/airy, dry inside, not very sweet), it can’t be a dense cake, so hesitant to add more coconut flour (unless just a bit) and I already used almost 2 tbsp psyllium – but I know there are recipes that use more psyllium for a fluffy bread-like texture.
I thought, since when you replace almond flour with defatted almond flour, you need to add much less defatted flour, so with that in mind, my macadamia version of the cake (much fattier) needs much more flour, but which kind / how much, etc.?

I don’t want to use whey or egg white powder (proteins to help the cake rise? Almonds are higher in protein than macadamia, I think).

I could maybe use a bit flax meal, but I’d like to try without if possible. So trying to juggle coconut flour – macadamia “flour” – psyllium. I can also add gelatin, but not sure it would help at all here (even if it’s a protein source).

- I was thinking about cutting fat in the recipe, but if I remove the butter, maybe the cake doesn't rise?! (I was told there's some emulsion forming between the cream cheese and the butter that makes this cake rise without gluten/wheat flour).
- Then I thought about removing the yolks and just using the 3 egg whites, but not sure I can eliminate all the yolks.
- Adding more flour (e.g. coconut, since I'm avoiding almond) until the dough has the right consistency can make it too dense? (and aiming for airy...)
- Adding more than 2 tbsp psyllium - is this unreasonable? (I don't want a cake that relies heavily on psyllium) - How much more would I have to add?
- And for some strange reason, I baked the original cake with whipped egg whites to hopefully make it raise even more (that was a previous experiment, before trying to sub almond flour for homemade macadamia "flour"), and it came out completely flat! :O So I'm not thrilled about adding whites to make this one rise...

How would you adjust / adapt the recipe?

Thanks a million in advance!

 

[Norcalbaker59]

You are not going to get brioche light airy texture with nut “flours”. Nuts are not grains. They do not have the same molecular structure as wheat, specifically the amino acids to create the bonds necessary to bind into a network to create extensibility and elasticity. Ground nuts produce heavy baked goods. When you restricted your diet, you have to accept the limitations of those restrictions. I say this as one who has lived gluten free for 12 years due to a medical condition. There are just some things you have to make peace with when you live with a restricted diet.

The egg whites did not make the original cake rise because the nut “flours” are not flours. They are ground nuts. Nuts are full of oil and very coarse. When stirred into the egg whites, the oils and coarse ground nuts deflate the egg whites.

Psyllium is a thickener. Adding more will not make a light airy texture, only a thicker gooey mixture. Remember, too, psyllium is used as a natural laxative, so there is a limit to how much you can use without undesirable side effects.

Coconut “flour” is the waste product of coconut milk and coconut cream. It is devoid of any all nutrients since all the liquid has been pressed out. It is not the same as desiccated coconut. Since all the liquid has been pressed out, coconut “flour” extremely hygroscopic. The only hydration in this recipe is from the eggs, diary, lemon juice, and brandy. I cannot imagine that this produces anything other than a heavy greasy eggy cake.