Preheat your oven to 300°F (150°C). Grease a 9x5 inch loaf pan.
Mix the sugar and cinnamon together in a shallow bowl.
Cut the thawed bread dough into 1-inch cubes. Dunk each cube into the melted butter, then roll it in the cinnamon sugar mixture.
Layer the coated dough cubes in the prepared pan, loosely stacking them to keep that signature pull-apart texture.
Bake for 30–35 minutes, or until the top is golden brown and the bread sounds hollow when tapped.
While the bread bakes, whisk together the powdered sugar, milk, and vanilla extract until smooth.
Once out of the oven, let the bread cool for about 10 minutes, then drizzle the glaze generously over the top. Try not to eat it all in one sitting. (I dare you.)