Possible Clues:

• Dessert starch
• Old talk up sweet pudding
• Staple food in Sumer, originally, back in time
• Staple food like this needs a good filling
• Sweet pudding gone after seconds
• Base of puddings in the past?
• Palm hence to cross with silver? The reverse!
• Drop round for sweet food
• Sink getting old food
• Edible powdery starch obtained from certain palms