Boil the potatoes and mash them while they are still hot. Allow to cool, then add lemon, ground yellow ají pepper, oil and salt. Mix well, forming a uniform dough with your hands. Separately combine the crabmeat with the mayonnaise, lemon juice, salt and togarashi.
To serve, arrange the causa de cangrejo in a cake pan, first placing a layer of potato paste, then adding the crabmeat salad. Cover with another layer of potatoes paste and place a few slices of avocado on it. Season with salt and lemon juice. Finally, cover with the top layer of potato paste.