Step 1: Prepare the Dough

1. Mix Dry Ingredients: In a large bowl, combine the flour, granulated sugar, instant yeast, and salt.
2. Combine Wet Ingredients: In a separate bowl, mix the warm milk, melted butter, egg, and vanilla extract.
3. Combine Mixtures: Pour the wet ingredients into the dry ingredients and stir until a dough forms. Knead the dough on a floured surface for about 5 minutes until smooth.

Step 2: Let the Dough Rise

1. First Rise: Place the dough in a greased bowl, cover with a kitchen towel, and let it rise in a warm place for about 1 hour, or until doubled in size.

Step 3: Prepare the Peach Filling

1. Mix Filling Ingredients: In a medium bowl, combine the diced peaches, brown sugar, cinnamon, cornstarch (if using), and lemon juice. Toss until well coated.

Step 4: Roll Out the Dough

1. Shape the Dough: After the dough has risen, punch it down and roll it out on a floured surface into a rectangle (about 12×18 inches).
2. Spread Filling: Evenly spread the peach filling over the rolled-out dough.

Step 5: Form the Rolls

1. Roll Up: Starting from the long edge, tightly roll the dough into a log. Pinch the seam to seal.
2. Cut Rolls: Slice the log into 12 equal pieces and place them in a greased baking dish.

Step 6: Second Rise

1. Let Rise Again: Cover the rolls with a kitchen towel and let them rise for another 30 minutes until puffy.

Step 7: Bake the Rolls

1. Preheat Oven: Preheat the oven to 350°F (175°C).
2. Bake: Bake the rolls for 25-30 minutes, or until golden brown.

Step 8: Make the Glaze

1. Combine Glaze Ingredients: In a small bowl, whisk together the powdered sugar, milk, and vanilla extract until smooth.

Step 9: Serve

1. Glaze the Rolls: Once the rolls are out of the oven, let them cool slightly before drizzling with the glaze.
2. Enjoy: Serve warm and enjoy!