Knead the dough. Make the dough: In a mixer bowl fitted with the dough hook, stir together all the flour yeast, milk, salt, melted butter and sugar. The dough should be slightly sticky but clear the sides of the bowl. Add a bit more flour or milk until the consistency is right. Knead on low until the dough is smooth and stretchy. You are done kneading when you can stretch out a golf-ball sized piece of dough and see translucent "windows" in the dough. If your machine is getting hot, let it rest a few minutes during the kneading process.
First rise. Cover and rise until doubled, about 90 minutes. This works best in a lightly warmed but turned-off oven.
Make the filling. Stir softened butter, brown sugar, cinnamon, and salt into a paste. Peel and chop peaches.
Make the crumble topping. Mix softened butter, flour, brown sugar, cinnamon, and salt until crumbly.
Assemble. Roll dough into a rectangle. Spread filling, sprinkle peaches, then half the crumble. Cut into 12 strips, roll up, and place in a greased 9x13 dish. Top with remaining crumble. Cover and rise 30 minutes. Preheat oven to 375°F.
Bake and glaze. Bake 25–30 minutes until golden and bubbling. Whisk powdered sugar with milk, drizzle over warm rolls, and serve.