Preheat the oven to 400°F
First, add freeze-dried strawberries into a blender or food processor and blend until a powder (it's okay if there are a few tiny pieces left).
Add strawberry powder along with flour, sugar, salt, and baking powder to a large mixing bowl. Stir to combine.
Incorporate butter by using a cheese grater (large side) or cutting it into the mixture with a fork until pea-sized pieces form.
Add chocolate chips and gently combine into the dry mixture.
Add milk, sourdough starter, vanilla, and egg. Mix gently using a spoon then use your hands to completely incorporate the flour.
Turn out the dough onto a lightly floured surface, knead dough gently for about 30 seconds.
Shape dough into a 2-inch high, 6-inch diameter circle.
Slice dough into 8 pieces like a pie, placing them 2 inches apart on a large parchment-lined baking sheet.
Bake for 17-20 minutes until the bottoms are golden brown and the tops are set.