In the kindest possible way, Hypatia and another friend have reminded me that the saint customarily associated with breasts is not so much Agnes as Agatha. No wonder I couldn't find the reference in The Leopard to the St Agnes cakes. Thanks to my friend (who may not relish being named here) for finding the description:
Scorning the table of drinks, glittering with crystal and silver on the right, he moved left towards that of the sweetmeats. Huge sorrel babas, Mont Blancs snowy with whipped cream, cakes speckled with white almonds and green pistachio nuts, hillocks of chocolate-covered pastry, brown and rich as the top soil of the Catanian plain from which, in fact, through many a twist and turn they had come, pink ices, champagne ices, coffee ices, all parfaits and falling apart with the squelch of a knife cleft; a melody in major of crystallised cherries, acid notes of yellow pineapple, and green pistachio paste of those cakes called 'Triumphs of Gluttony', shameless 'Virgins' cakes' shaped like breasts. Don Fabrizio asked for some of these, and as he held them on his plate looked like a profane caricature of Saint Agatha claiming her own sliced-off breasts. 'Why didn't ever the Holy Office forbid these puddings when it had the chance? 'Triumphs of Gluttony' indeed! (Gluttony, mortal sin!) Saint Agatha's sliced-off teats sold by convents, devoured at dances! Well! Well!'
And for the pics?