You are a sauce-flavored cake maker. What kind of bulking agent should you use? Why do you ask us instead? Anyway, I also like soy sauce cakes, and I have made them several times at home. According to the online recipes, the authentic Hubei Enshi Maotai-flavor cake (Tujia Maotai-flavor cake) is made of dry yeast and baking powder, while some netizens just add warm water (about six and a half parts of water per catty) to the flour, and the sauce-flavor cake is also delicious. I just don't use yeast and baking powder to make it, which is similar to the taste of people queuing to buy it in the morning market. The key to cooking any delicious food is to really study, ponder and experiment after you have a recipe, so as to master the essentials. In fact, no one is worse than anyone else. The key to a sauce-flavored cake is the frying of those sauces.