In a large mixing bowl, combine your sourdough discard, all-purpose flour, and a pinch of salt. Cut in the cold unsalted butter until the mixture resembles coarse crumbs. Chill in the refrigerator for 30 minutes.

Roll the dough on a floured surface into a rectangle about 1/4 inch thick. Fold into thirds like a letter, and roll out again. Repeat this rolling and folding process two more times.

Beat the cream cheese with powdered sugar until creamy and smooth. Set aside for spreading.

Roll out the dough into a 1/4 inch thick sheet, cut into 4-6 equal squares, place a spoonful of filling in the center of each, add fresh raspberries, and fold corners inward to seal.

Arrange on a parchment-lined baking sheet, cover loosely with plastic wrap, and let rest in a warm spot for 20-30 minutes while preheating oven to 400°F.

Brush tops with egg wash if using, bake for 18-22 minutes until golden brown. Let cool slightly before serving warm.