For the Dough:

1. In the bowl of a stand mixer, combine 4 cups of the flour, the sugar, yeast, and salt.
2. Place the butter and peanut butter in a small bowl and heat in the microwave until melted and smooth, about 30 seconds.
3. Add buttermilk to a glass measuring cup and heat in the microwave until it reaches a temperature of 120°F (use the instructions on your yeast package to see what the range should be. You don’t want it too hot or it will kill the yeast). Whisk in the melted butter and peanut butter.
4. Fit the mixer with the paddle attachment. Turn on the mixer to combine the dry ingredients and then slowly add in the buttermilk mixture and the eggs. Mix until combined.
5. Switch to the dough hook attachment and mix for 10 minutes. Add in another ¼ cup of flour to ensure that the dough isn’t too sticky. The dough should be very tacky and moist.
6. Spray a large bowl with cooking spray and scrape the kneaded dough into the bowl. Cover with plastic wrap and allow it to rise for 2-3 hours, or until doubled in size.
7. Punch down the dough and then roll it out on a floured surface to form a large rectangle.

For the Filling:

1. Evenly spread out the butter over the surface of the dough, leaving a ½-inch border around the edge. Then, sprinkle the brown sugar, cinnamon, and chopped chocolate evenly over the butter.

Forming the Rolls:

1. Carefully loosen the dough from the surface on one long edge of the rectangle. Slowly and carefully roll the dough into a tight log. Pinch the seam closed and then gently even out the log so it is the same diameter from end to end. Slice the log in half and then cut each half evenly into thirds. You should now have six pieces of the log. Slice each piece in half to make 12 cinnamon rolls.
2. Line a large rimmed baking sheet with parchment paper and then arrange the rolls on the pan. Cover with plastic wrap.
3. At this point, you can place the pan in the fridge for up to 16 hours to make the next day. Or, you can proceed with allowing them to rise for another hour at room temperature. If keeping in the fridge, remove one hour before you are ready to bake and allow them to double in size again.
4. Bake the rolls in a 350°F oven for 20-25 minutes or until golden brown on top.

For the Frosting:

1. While the rolls are baking, place the butter, cream cheese, and peanut butter in the bowl of a stand mixer. Beat until light and creamy. Add in the vanilla and powdered sugar, adding the sugar gradually until the frosting is thick and creamy. Add in the milk, one tablespoon at a time, if needed to thin out the frosting to a spreadable consistency.
2. Spread generously on the rolls as soon as they come out of the oven. Allow them to cool slightly before serving.