Rinse the peaches with water, pat them dry, and slice them into small chunks.
Place the peach chunks into a strainer sitting over a bowl to let excess juices drain off while starting the scone batter.
While the peach chunks sit, add flour, cane sugar, brown sugar, salt, and baking powder into a large mixing bowl.
Incorporate cold stick butter by using a cheese grater (large hole side) or cutting it into the mixture with a fork until pea-sized pieces form. Stir to evenly distribute butter pieces.
Dump peach chunks on to a paper towel or kitchen rag then pat them to get off excess moisture.
Add peach chunks to the bowl of dry ingredients and stir to evenly coat each chunk.
Add milk, sourdough discard, vanilla, and egg. Mix just until combined. Use your hands to completely incorporate the flour(this may take 30 seconds to 1 minute). The dough will sticky.
Optional – At this point you can either continue the recipe or place the batter covered in the fridge for 12-24 hours to long ferment for more sourdough fermentation benefits.
To continue the recipe, preheat oven to 400 degrees Fahrenheit and cover a sheet pan with parchment paper.
Place the bowl of dough into the freezer (not the fridge) for 15-20 minutes to chill before shaping into scones. (You need to do this even if you did the optional overnight fermentation). If you skip this your scones will be hard to shape.
Once chilled, turn dough out on to a floured surface and shape it into a 2-inch-high, 6-inch-diameter circle. Don't overwork the dough. The dough will be sticky!
Slice the dough into 8 pieces like a pie, placing them 2 inches apart on a parchment-lined sheet pan.
Bake for 20-24 minutes until golden brown. Place on a cooling rack then enjoy!