Beat the egg. Remove 1 tbsp of egg and set aside for glazing the loaf later. Chop half the peanuts and set aside.
In a medium bowl, combine the flours, salt, yeast and remaining egg. In a blend, combine water and peanut butter and process until smooth. Immediately add this to the flour and stir with a wooden spoon or your hand until it forms a wet, sticky dough without lumps. Add whole peanuts and stir until evenly distributed. Cover with a linen towel and let stand at room temperature until dough is more than doubled in size and pocked with bubbles, at least 12 hours.
Sprinkle the dough with flour and scrape out onto a floured work surface. Pat and pull the dough into a rectangle, 8 inches by 12, with the long side facing you.
Spread the jam evenly across the surface, leaving a 1" border all around. Fold 1/3 of the rectangle over, lifting from the edge further away from you. Fold over towards you a second time, forming a three-layered roll with the seam towards you. Pinch the seam shut and tuck the ends under to contain the jam.
Lightly spray a large loaf pan with non-stick spray. Sprinkle half the chopped peanuts in the bottom of the pan, then lay the roll into the pan, seam side down. Sprinkle the remaining chopped peanuts on top. Cover with a linen towel and let rise until doubled, about 1 hour. When poked, it should hold the impression; if it springs back, wait another 15 minutes.
Preheat oven to 450°F for at least 15 minutes (time it to match the rise). Brush the loaf with the reserved egg. Bake until golden, about 75 minutes. If the peanuts start to get too dark, cover loosely with foil. When done, invert pan onto a baking rack then turn loaf right side up to cool.