In a mixing bowl, combine the warm milk, warm water, and sugar. Stir until the sugar dissolves. Sprinkle the yeast over the mixture and let it sit for about 5-10 minutes until it becomes frothy.
Once the yeast is activated, add the melted butter to the mixture. In a separate bowl, combine the flour and salt. Gradually add the flour mixture to the wet ingredients, stirring with a spatula until a soft dough forms.
Transfer the dough to a lightly floured surface and knead for about 5-7 minutes, until the dough is smooth and elastic. Place it in a greased bowl, cover it with a kitchen towel, and let it rise in a warm place for about 1 hour, or until it doubles in size.
In a small bowl, mix together the sugar and cinnamon. Set aside. Melt the remaining 1/2 cup of butter in another bowl.
Once the dough has risen, punch it down and divide it into small pieces (about 1 inch in size). Dip each piece in melted butter, then roll it in the cinnamon sugar mixture. Layer the coated dough balls in the prepared Bundt pan.
Once you’ve layered all the dough balls, sprinkle the dark brown sugar over the top for that extra caramelized sweetness.
Cover the pan with a kitchen towel and let it rise again for about 30 minutes, until puffy.
Preheat your oven to 350°F and bake the Monkey Bread for 30-35 minutes, or until golden brown and cooked through. Let it cool in the pan for about 10 minutes before inverting it onto a serving plate.