In a bowl, combine the sourdough starter, all-purpose flour, granulated sugar, and water. Knead until the mixture is cohesive, then cover and let it rise for 10-12 hours until doubled in size.

Warm the milk to about 90-100ºF. In a stand mixer bowl, mix the levain, warmed milk, melted butter, sugar, egg, salt, and most of the bread flour. Knead for a few minutes, adding flour until the dough becomes slightly tacky.

Transfer the dough to a container, cover it, and let it rise in a warm place (78-80ºF) for about 4 hours until it's puffed and elastic.

After the bulk fermentation, cover the dough and refrigerate it overnight, or if you're eager, proceed to shaping right away.

Crush the freeze-dried strawberries into a fine powder. Mix this with melted butter, granulated sugar, and flour until it forms a thick paste. Set this aside for filling.

Dice the strawberries and mix half of them with granulated sugar, then refrigerate. The other half will be used to top the rolls later.

Prepare a 9 by 13 pan. Roll out the dough into a 16 by 12 rectangle, spread the filling evenly, and sprinkle the diced strawberries on top. Carefully roll the dough tightly and cut it into 8 pieces.

Place the rolls in the prepared pan, cover, and let them rise in a warm place (80-85ºF) until puffed, approximately 3-4 hours.

Preheat your oven to 350ºF. Bake the rolls for 28-30 minutes until they are fully baked and golden brown.

For the frosting, whip together the softened butter and cream cheese. Gradually add the powdered sugar, heavy cream, vanilla extract, and salt, whipping until the mixture is light and fluffy.

Once the rolls are out of the oven, spread the frosting on the warm rolls and top with the sugared strawberries for a delightful finish.