First, make your peanut butter chunks. On a sheet pan lined with parchment paper, add 24 dollops of peanut butter, each about 1 teaspoon. Place in the freezer and allow to harden for at least 1 hour, but preferably 3 hours. You can also do this overnight.
Preheat your oven to 425 degrees F. In a food processor, pulse the dry ingredients together (2 cups all purpose flour, 1 tablespoon baking powder, ¼ cup sugar, ½ teaspoon salt). Sprinkle in the butter cubes and pulse until the mixture resembles coarse crumbs with a few slightly larger butter lumps, about 12 pulses. If you don’t have a food processor, whisk the dry ingredients together in a bowl, and cut in the butter using 2 butter knives or a pastry blender. Transfer to a large mixing bowl.
Next, process the peanuts until you have a mix of fine and coarse crumbs. Mix with 1 tablespoon of sugar and set aside.
Mix the beaten egg yolk with the sour cream and stir into the dry mixture to make the dough. At this point, if the dough is still dry and not coming together, drizzle in 3 tablespoons of milk 1 tablespoon at a time until the dough is formed (you may not need all 3 tablespoons). Just before the dough fully comes together, sprinkle over the frozen peanut butter chunks.
Gently mix with your hands to bring the dough together and distribute the peanut butter chunks. They’ll smear a little bit, but try to keep them as whole as possible. Do not overwork the dough. As soon as the dough is cohesive enough to form into scones, you’re good to go.
On a floured surface, shape the dough into a square, about 1 inch thick. Cut the large square into 4 smaller squares, and then cut each small square in half on the diagonal to form 8 triangles. Transfer the scones to a parchment lined baking sheet, spaced a couple inches apart.
Using your fingers, make a crosshatch in each scone with your finger. You’re making a “well” to put the jam into. Using a spoon, carefully spoon the jam into the well. If you need to soften your jam to do this, microwave it for 15 seconds to loosen it up. Brush the scones with the 2 tablespoons of milk, avoiding the jelly, and sprinkle with the peanut sugar.
Bake the scones at 425 degrees F until the tops are light brown, 15-18 minutes. Cool on a wire rack for 10 minutes before serving. Eat these with a tall glass of milk!