Bread
Someone in this building is baking bread. I could smell that peculiar sweetness that only yeast can yield, as I came up the stairs from checking my mailbox. It reminds me of long ago days when my grandmother would bake an entire army's worth of bread in a day; every flat surface, the couches and chairs counted, adorned with covered dishes of rising dough. There was and is nothing like the taste of bread fresh from the oven covered in butter. I don't think anything could aggravate feelings of hunger as does the smell of baking bread, or cooking onions.