In the bowl of your stand mixer with dough hook attached, add flour, yeast, salt, sugar, buttermilk, and egg. Mix until a rough dough forms.
Rest the dough for 10 minutes.
After 10 min, add your butter in two pieces and mix the dough on low until a smooth elastic dough has formed (10-20 minutes).
Dough will be sticky but manageable. Remove dough from bowl, lightly grease the bowl. Shape dough as best as you can into a ball shape and then place back into the greased bowl. Cover and allow to proof in a warm spot for 1-2 hours or until the dough has doubled in size.
Punch down the dough and move the dough to a workspace.
Grease a 9x5 loaf pan generously.
Using a bench scraper or knife, divide the dough into small chunks about 1-2 inches wide. They do not need to be identical and it's okay if some are a little smaller or larger than others. For me this was about 30-35 pieces of dough.
Add half a cup of granulated sugar and 1 tablespoon of cinnamon to large ziplock bag or bowl.
Loosely form your dough pieces into roundish shapes and drop them into the cinnamon sugar, completely coating them. Reserve whatever cinnamon sugar is left.
Once all the dough balls are coated, layer them in your loaf pan.
Cover your loaf pan and allow to proof in a warm spot for 30-60 minutes. Again the dough will have puffed up and be nearing the top of the pan.
Preheat your oven to 350°F
In a sauce pan, melt your butter over medium low heat. Once the butter has melted, add your brown sugar, salt, vanilla, and any leftover cinnamon sugar and stir.
Once the mixture becomes more of a caramel sauce, carefully pour it over the dough.
Place your loaf pan on a baking sheet (don't skip this! The caramel sauce tends to bubble up and can end up burning at the bottom of your oven) in the oven on the center rack and bake for 25-30 min.
Remove your monkey bread from the oven and allow to cool for about 5 minutes before flipping the pan over onto a plate or serving dish.
Enjoy while warm!
