Mix protein, sugar, powder, almonds, starch and beat with a mixer. Put on parchment with small rectangular meringues and put in the oven for 4.5 hours at 100 degrees.
Mix cream with butter and bring to a boil. Mix sugar and yolks and add to butter. Strain. Boil in a water bath for 1 hour.
Roast the walnuts. Grind nuts and prunes. take 2 square meringues, 30 g each. Lubricate each meringue with cream. Sprinkle one meringue on the cream with nuts and prunes. Cover the second. Coat the outside with cream and sprinkle everything with almond flakes.