Puree the raspberries using a blender or food processor, reserving all juices if using thawed raspberries.

In a stand mixer, mix flour, milk, sourdough starter, pureed raspberries, eggs, sugar, salt, optional freeze-dried raspberries, and optional pink food coloring on low speed for 3-4 minutes until incorporated.

Add softened butter and mix on medium speed for 10 minutes until the dough is smooth and elastic. Add additional flour if necessary.

Transfer the dough to a greased bowl, cover, and let it rise for 4-6 hours until doubled in size, performing stretch and folds every 30 minutes.

Transfer the dough to the refrigerator to cold-proof overnight (8-12 hours).

Roll out the chilled dough into a 24-inch by 14-inch rectangle, ¼’’ – ⅓ inch thick. Wrap in plastic and freeze for 1 hour.

Remove from the freezer, trim edges for a clean rectangle, and cut into six 4-inch by 14-inch rectangles. Cut each rectangle into 12 triangles.

Roll each triangle tightly into a croissant shape and transfer to a lined baking sheet.

Let the croissant donuts rise until doubled in size (2-5 hours).

Heat frying oil in a pot to 375°F. Fry donuts in batches for 1 minute on each side until golden brown, then cool on a rack.

Toss the cooled donuts in granulated sugar until evenly coated.

Poke a hole in the bottom of each donut and pipe in pastry cream and raspberry jam.