Add all of the dry ingredients (dough only not the topping) to a stand mixer bowl. Then give a quick mix with a whisk.
Then add the milk and egg. Turn the mixer on low to incorporate everything. If needed use a spatula to scrape down the bowl.
Slowly increase the speed of the mixer, mix on high for three minutes.
Put some flour of your surface and scrape your dough out of the bowl and form it into a ball. The dough is very sticky but just do the best that you can. Cover with plastic wrap and let it rest for ten minutes.
After the dough has rested put about a teaspoon of flour on your surface and knead for three or four minutes. Then form it into a ball and add to a bowl and cover. Let it rise until doubled in volume.
After the dough has doubled in size punch it down and form into eight to twelve individual balls.
Cover the balls and let them rise until close to doubled in size.
Crumb Topping
Add the the peanut butter and butter to a bowl and mix.
Add and mix in the honey and raw sugar.
Add about 1/3 of a large egg and mix.
Add and mix in mix in the dry milk, salt and baking powder.
Dump in the all purpose flour and use your hands to mix it in.
Make the Soboro-ppang
When your dough balls are ready roll them into balls and brush with egg or milk.
Top the dough balls with with crumb mixture.
Place your dough balls on a sheet pan lined with parchment paper and add more crumb mixture and press them kind of flat.
Let them rise until they have almost doubled in size.
Preheat oven to 350 F
Bake for 20 minutes at 350 F. After 15 minutes turn 180 degrees.