Cover three large baking pans with paper that has been well oiled with washed butter. Over these dredge powdered sugar. Melt in a cup one ounce of Walter Baker & Co.'s Premium No. 1 Chocolate. Separate the whites and yolks of four eggs. Add to the yolks a generous half cupful of powdered sugar, and beat until light and firm. Add the melted chocolate, and beat a few minutes longer. Beat the whites of the eggs to a stiff, dry froth. Measure out three-fourths of a cupful of sifted flour, and stir it and the whites into the yolks. Drop the mixture in teaspoonfuls on the buttered paper. Sprinkle powdered sugar over the cakes, and bake in a slow oven for about fourteen or fifteen minutes. Which method of development is used in this recipe?