T his is based on Artusi's recipe, and is as easy as it is delightful. H alve the pine nuts crosswise, and peel and sliver the almonds.
M elt the butter in a double boiler.
Beat the eggs and the sugar till the mixture turns pale yellow. Add the lemon rind, the flour, a bit at a time, the butter, and, finally, the baking powder. Pour the batter into 9-inch a copper pan that's been buttered and dusted with flour and powdered sugar or bread crumbs, and sprinkle the surface of the cake with the nuts. D ust the Mantovana with powdered sugar and serve it cold. It goes quite well with dessert wine, and will keep for several days, wrapped in aluminum foil.