STEP 1/4
Castella cuts off the dark parts with a knife, grinds only the yellow parts finely in the blender, and grinds the bananas finely without lumps in the blender. And fold powdered coffee and sugar in warm water without lumps.
STEP 2/4
Mix mascarpone cheese, sugar, and finely ground bananas in a bowl first and adjust the toughness to a soft state with whipped cream. If you mix only banana and cheese, it's a bit dry, so if you soften it with whipped cream, it comes out smoothly when you put it in the piping bag. Put the well-mixed cheese dough in a piping bag, place a layer of castella powder in a cup, and sprinkle coffee liquid on top of it to moisten the castella in the coffee liquid. Squeeze 1/2 of the cheese dough into a piping bag over the coffee-sprinkled castella.
STEP 3/4
Place sliced bananas on top of the cheese dough, add the rest of the castella powder, sprinkle the coffee liquid, put the banana slice again, and squeeze all the rest of the cheese dough at the end to flatten the top.