In a large bowl, whisk together the flour, sugar, baking powder, cinnamon, and salt.
In a separate bowl, mix the milk, egg, and vanilla extract until smooth.
Pour the wet ingredients into the dry ingredients and stir gently until just combined. Do not overmix.
Carefully fold in the diced peaches, making sure they are evenly distributed.
Heat oil in a deep pan over medium heat until it reaches about 175°C (350°F).
Using a spoon, drop small portions of batter into the hot oil.
Fry for 2–3 minutes per side, turning once, until golden brown and cooked through.
Remove the fritters with a slotted spoon and place them on paper towels to drain excess oil.
For the glaze, whisk powdered sugar, milk, and vanilla until smooth, then drizzle over warm fritters.