Preheat your oven to 350°F (175°C) and grease a 9×5-inch loaf pan.
In a mixing bowl, whisk together granulated sugar, whole milk, vegetable oil, egg, and vanilla extract until smooth.
In another bowl, whisk together flour, baking powder, and salt until evenly mixed.
Fold the dry ingredients into the wet mixture until just combined.
Fold in diced peaches and pour the batter into the prepared loaf pan. Bake for 55-60 minutes until golden brown.
Let the bread cool in the pan for 10 minutes, then transfer to a wire rack. Prepare the glaze by mixing powdered sugar, melted butter, diced peaches, and vanilla extract until smooth and spread over the bread.