If using 100 g of egg whites (12 egg whites): you will need 100 g of egg whites, 100 g of butter, 80 g of sugar, 50 g of cake flour, 60 g of almonds, and 20 g of honey.
If you are adding baking powder, use 1/8 scant teaspoon for 100 g of egg whites.
You can make either caramelized butter or melted butter.. Measure the caramelized butter when it's done.
Add the almond powder and sugar into a bowl and mix well with a whisk.
Add the egg whites and mix without whipping or forming peaks.
Add the honey and mix some more without whipping or forming peaks.
Sift the cake flour over the bowl and mix (don't whip) until the mixture is no longer lumpy. If you are using baking power, combine with the cake flour first.
Add the Step (3) butter little by little and mix, being sure not to make foamy.
When the mixture is well blended, let it sit for 3 ~ 12 hours in the refrigerator. ※I baked it without resting the batter, as shown in the picture of the finished product. It's okay to skip this step.
Pour into the butter greased mold, and bake for 15 ~ 20 minutes in the oven at 180℃ (350℉).
They are freshly cooked in this picture. They will be moist the next day. If you want to taste them, it will be better to do so the following day.
If you don't want them too sweet, reduce the sugar amount by 50%.
I will upload the pictures for each step some other day when I have time. It's my own style, so if good tips come up, I will modify the recipe.
Using a small amount of baking powder makes them taste store-bought. But if you use too much of, they won't be financier cakes anymore, so please be careful.
I made custard cream with leftover egg yolks and used it to make Mille crêpes. "Very easy custard cream in a microwave": https://cookpad.com/en/recipes/145241-very-easy-custard-cream-in-a-microwave