**Make the Peach Jam**: In a pot, combine the cubed peaches, granulated sugar, and lemon juice. Cook over medium heat for 12-15 minutes, mashing occasionally, until the peaches are juicy and starting to thicken. Mix the cornstarch and water together, then stir it into the peach mixture. Cook for an additional 2 minutes, then transfer the jam to a bowl and let it cool completely.
**Make the Tangzhong**: In a small pot, whisk together the water and bread flour. Cook over medium heat, whisking constantly for 4-5 minutes until it becomes a paste-like consistency. Transfer to a bowl and set aside.
**Make the Dough**: In a stand mixer bowl, combine the bread flour, granulated sugar, instant yeast, and sea salt. Add the milk, heavy cream, egg, vanilla, and the prepared tangzhong. Knead on low speed with a dough hook for 2 minutes until a rough dough forms.
With the mixer running on low, gradually add the softened butter, one tablespoon at a time, allowing it to fully incorporate before adding more. Continue kneading for another 8-10 minutes until the dough is smooth and elastic.
Remove the dough from the bowl and shape it into a smooth ball. Place it seam-side down back into the mixing bowl. Cover with plastic wrap and let it rest for 30 minutes.
**Assembly**: Preheat your oven to 325°F (162°C) and line a 9x13 baking dish with parchment paper. In a bowl, mix together the butter, brown sugar, and cinnamon until smooth.
Roll the rested dough on a lightly floured surface into a 15x21-inch rectangle, with the longest side facing you. Spread the cinnamon sugar mixture over the dough, leaving a 1/2-inch border at the top. Spread the peach jam on top, then layer the thinly sliced peaches.
Use a pizza cutter to slice the dough into twelve 1 3/4-inch strips. Roll each strip away from you and carefully transfer them to the lined baking pan.
Cover the pan with plastic wrap and let it rise for 1-2 hours, or until the rolls double in size.
While the rolls are rising, prepare the crumb topping by mixing the flour, sugar, cinnamon, and melted butter in a bowl until crumbly.
Once the rolls have risen, sprinkle the crumb topping over them. Bake for 30-40 minutes, or until the tops are golden brown. Let the pan cool on a wire rack.
**Make the Cream Cheese Glaze**: In a bowl, mix the cream cheese, butter, and powdered sugar until smooth. Whisk in the heavy cream. Spoon the glaze over the warm rolls and enjoy!