Peel and slice the peaches. Toss them well in cinnamon sugar, then place them on a wire rack.
Dust the peaches lightly with cornstarch. This gives the batter something to hold onto.
In a bowl, whisk together the milk, egg, and vanilla.
Add the flour, salt, baking powder, cinnamon, and sugar. Mix until you have a smooth funnel cake-style batter.
Dip the peach slices in the batter, letting excess batter drip off.
Fry in hot oil until golden brown and crisp. Drain on a wire rack or paper towel.
Serve warm with an extra sprinkle of cinnamon sugar. Add ice cream, whipped cream, or a drizzle of caramel if you want to make them extra special.