Cake Sponge
Egg Yolk Mixture Egg Yolks: 4 pieces Corn Oil: 45 g Milk: 108 gCorn starch: 20 g
Cake flour: 100 g Purple sweet potato flour: 9 g Egg whites: 4Lemon juice or white vinegar
A few drops Sugar 75 g Filling Whipping cream 300 g Sugar 16 gSeparate the egg whites and yolks into a clean, oil-free, water-free container. The egg whites are not needed for now; place them in the refrigerator.
Place milk and corn oil in a mixing bowl, and stir until emulsified.
Sift in cake flour, corn starch, and purple sweet potato powder. Mix with a zigzag motion until no dry flour remains, then add egg yolks. Continue mixing in the same manner until the batter reaches the following state: lines appear and slowly disappear. If the batter feels dry, add milk in small amounts; if it feels wet, add cake flour in small amounts. Take out the egg whites, add a few drops of lemon juice or white vinegar, and beat with an electric mixer until large fish-eye bubbles form, then add one-third of the sugar. Continue beating until lines just appear and immediately disappear, then add another one-third of the sugar. Preheat the oven. Continue beating until distinct lines appear, then add the remaining one-third of the sugar. Continue beating until soft peaks with a curved hook form.Take 1/3 of the meringue and mix it into the egg yolk batter using a cutting and folding method until well combined.
Pour the mixture into the remaining meringue and mix in the same manner, working as quickly as possible to prevent the meringue from deflating. The finished cake batter. Pour the cake batter into a 28*28 square pan from a height of 30 cm. Level the surface, then tap the pan a few times to release air bubbles. Bake in the oven at 135°C top / 145°C bottom on the middle rack for about 30 minutes. Cover with aluminum foil in time to prevent over-browning. Once baked, remove the cake layer from the oven and let it cool for later use. Slice the cake according to the size of the container. Whip cream with sugar to 70% stiffness. Add fruit jam and continue whipping to 90-100% stiffness, until it holds a piping consistency. Transfer to a piping bag and set aside. Layer one slice of cake, followed by cream, fruit, and chocolate crisp pearls. Repeat to make three layers.
