Pit and chop peaches (skin on) into a 1-inch dice.
In a small bowl, add milk and vinegar. Allow to rest for 5 minutes, minimum.
In a large bowl, whisk together flour, sugar, baking powder, crushed cardamom seeds, and salt.
To the milk, add egg, melted butter, and whisk. Gently fold this mixture into the dry ingredient mixture until just combined. Fold in the peaches.
Meanwhile, heat 3 inches of oil in a medium heavy-bottomed pot over medium-high heat (a candy thermometer will register 350F). Test the oil: a tiny drop of batter should sizzle and float to the top.
Working in batches, drop a heaped tablespoon into the oil (using the aid of a second spoon to nudge the batter into the oil).
Fry, agitating and turning the fritters occasionally, for 1½ to 2 minutes, or until they turn golden and are cooked through.
Remove them from the oil and transfer to a large platter lined with paper towels. Adorn with powdered sugar and enjoy.