Vanilla! It wasn't an intentional secret ingredient; actually, it was more of happy accident. In the middle of cooking, Abby reached for the sugar and realized that she only had vanilla bean-infused sugar on hand. And guess what? It totally worked. The vanilla was not overpowering (she didn't use a lot of sugar, just enough to add a little extra sweetness) but it was subtly aromatic and helped balance the acidity of the tomatoes.
Searching online, we found scant references to vanilla in tomato soup. Have any of you used vanilla – sugar, bean, or extract – in tomato soup?