In the bowl of a stand mixer, combine the water, buttermilk, yeast, 4 T melted butter, sugar, 1 tsp fine sea salt and eggs with paddle attachment. Mix until all ingredients are combined.
Add the 4 cups of flour and mix until just combined. Switch to dough hook attachment and knead dough for 8 minutes. If dough feels excessively sticky, add a bit more and mix until incorporated. Dough should be cleaning the sides of the bowl and clinging to the dough hook.
Spray a medium sized bowl with nonstick spray. Place dough in the bowl and turn to coat all sides. Cover with a clean kitchen towel and let rise until doubled in size, about 1 & 1/2 hours.
Brush vegetable shortening on the inside of cast iron pot or bundt pan (see notes)
Turn dough out onto slightly floured countertop. With hands, gently pull on dough, spreading out until about 1/2 inch in thickness. Cut into small pieces with a pizza cutter (about 60-80 pieces). Quickly roll into little balls - don't worry about them being very smoothed and rounded out, they will puff up and smooth out as they rise. (This is the perfect time to let the kids help out!)
Prepare the ingredients for the Topping by combining all together in a small bowl. Pour 1/3 of it into the prepared pan and spread to coat the bottom of the pan. Add 1/2 of the dough balls, layering evenly. Pour another 1/3 of the Topping over the tops of the rolls. Add the second half of the rolls. Pour the remaining 1/3 of the mixture on top of the rolls.
If using a cast iron pot, cover with lid. If using a bundt pan, cover with plastic wrap that has been sprayed with nonstick spray. Allow to rise until doubled in size, about 1 hour.
Preheat oven to 375°F. Bake for 30-32 minutes or until golden.
Leave bread in the pan for 5 minutes. Place a large plate or platter on top of the pan and quickly turn over, releasing the bread from the pan.
Serve hot but be careful not to burn your fingers pulling apart that gooey goodness!