Separate the egg whites from the yolks. Next, put the two egg yolks and the sugar in a bowl. Mix well with a whisk until a whitish mass is formed.
Add the rice beverage while continuing to mix. When everything is well mixed, it is time to add the cornstarch, the rice flour and the yeast sachet. Mix everything together with a spatula until the batter is uniform.
Add the grated carrot and apple. Mix to integrate all the ingredients.
In another bowl, and with the help of a whisk, beat the two egg whites until stiff and gently fold them into the batter. Mix as little as possible so as not to reduce the volume and to make it as fluffy as possible.
Put the batter in a mould. To prevent the sponge cake from sticking and to remove it easily, line with a little oil and baking paper in it. Bake the batter in the oven at 180 degrees for 30 minutes.