In a medium saucepan, combine cubed fresh peaches, granulated sugar, and lemon juice over medium heat. Cook for 12-15 minutes until thickened, stirring frequently. Once thickened, stir in a cornstarch mixture and cook for an additional 2 minutes.

In a separate small saucepan, combine equal parts flour and water, cooking over low heat until thickened, about 2-3 minutes. Let it cool slightly before mixing with all-purpose flour, sugar, instant yeast, salt, milk, a beaten egg, and vanilla extract in a large mixing bowl. Knead until smooth for about 10-11 minutes.

While the dough is resting, prepare the crumb topping by mixing melted butter with flour, brown sugar, granulated sugar, and ground cinnamon in a bowl. Use your fingers or a fork to combine until crumbly and well-blended. Chill the crumb topping in the refrigerator while your dough rises.

After the dough has risen, turn it out onto a floured surface and roll it into an 18x15-inch rectangle. Spread the prepared brown sugar filling evenly across the dough. Then, layer the peach jam over the filling followed by an even distribution of sliced peaches.

Starting from one long edge, roll the dough tightly into a log. Cut the log into 12 even strips. Place the strips, cut sides up, into a greased baking dish. Cover with a kitchen towel and let them rise for about 1 hour until doubled in size.

Preheat your oven to 325°F (162°C). Once ready, sprinkle the chilled crumb topping generously over the rolls. Bake for 30-35 minutes until golden brown and puffy.

While the rolls are baking, make the creamy frosting. In a medium bowl, whip together softened cream cheese and butter until smooth. Gradually mix in powdered sugar and heavy cream until you achieve a thick, drizzling consistency.

Once the rolls are baked and golden, let them cool slightly before drizzling the cream cheese frosting over the warm rolls.