This soup captures summer's best flavors: sweet corn, juicy peaches, and fragrant basil.
With a sharp, heavy knife, cut the kernels from the corn cobs and place cobs and kernels in a soup pot. Add the broth, water, miso, onion, garlic, and cayenne. Peel, pit, and finely chop 2 of the peaches and add to the pot. Bring to a boil over high heat, lower the heat and simmer, uncovered, stirring occasionally, until the corn and peaches are very tender, about 30 minutes.
Use tongs to remove and discard the corn cobs and cool the soup to room temperature. Purée half of the soup in a blender and return to the pot. Stir in the almond milk. To serve the soup hot, reheat gently over medium heat, stirring frequently but do not allow to boil. To serve cold, refrigerate until chilled.
Halve, pit, and dice the remaining peach. Ladle the soup into bowls and garnish with the peach and basil.