Preheat oven to 400°F and line a baking sheet with parchment paper.

Add flour, cocoa powder, sugar, salt, and baking powder into 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 in butterscotch chips, and stir to combine.

Add milk, sourdough starter, peanut butter (warm if it's super thick), vanilla, and egg. Mix using a spoon until all flour is incorporated into the dough. It may be crumbly. Use your hands to completely incorporate the dry mixture into the wet. Add 2 Tablespoons more milk if dough won't come together.

Turn out dough onto a lightly floured surface, knead dough gently for about 5-10 seconds to create a smooth texture. If your dough is sticky use a little flour to help.

Shape dough into a 3/4-inch high, 8-inch diameter circle (doesn't have to be exact).

Slice dough into 8 pieces like a pie and place them 2 inches apart on the parchment-lined sheet pan.

(OPTIONAL) Stick the pan in the freezer for 10 minutes to set the dough for a better scone shape while baking (you can do this up to 3 months if you're making them ahead).

Bake for 18-20 minutes until the bottoms are golden brown (stick a toothpick or knife into a scone, if it comes out clean they're done).