Make the Dough

1. Beat 1 c butter in the bowl of a stand mixer fitted with the paddle attachment on medium-low speed until butter is smooth and pliable but still cold (about 1 minute). Scrape into a medium bowl; set aside. Save the mixer bowl because you’re going to use it again in a minute (no need to wash).
2. Heat the milk to 110°–115°F. Whisk the milk and yeast in a small bowl to dissolve the yeast, then let sit until foamy (about 5 minutes).
3. Meanwhile, whisk the flour, sugar, and salt in the reserved mixer bowl to combine. Add the yeast mixture and eggs. Fit the bowl back onto the mixer, attach the dough hook and beat on low speed, gradually increasing the mixer speed to medium as the dry ingredients are incorporated, until the dough comes together around the hook. Continue to mix on medium speed until the dough is smooth, elastic, and no longer sticking to the sides of the bowl (about 5 minutes). Add more flour by the tablespoonful as needed if the dough isn’t pulling away from the bowl cleanly.
4. With the motor running, gradually add the reserved butter about a tablespoonful at a time, waiting until it is absorbed before adding more. This process can take several minutes, so be patient. When you’re finished adding the butter, the dough will be extremely smooth, soft, and supple but not sticky. Place the dough in a large buttered bowl and cover. Let sit in a warm, draft-free spot until nearly doubled in size (about an hour).
5. Uncover the dough and punch down several times to deflate. Line a 13×9″ baking dish with plastic wrap, leaving a generous overhang on all sides. Place the dough in the pan and press into an even layer, working all the way to the sides of the pan. Fold the plastic up and over the dough, eliminating any air pockets between the dough and the plastic. Chill the dough in freezer until firm to the touch (20–30 minutes).

Make the caramel sauce:

1. Melt butter and sugar over medium heat, stirring for about 5 minutes, until the sugar is dissolved. Add the cream, stirring as you bring to a boil. Simmer until the mixture is slightly reduced and thickened, about 10 minutes. Note: the mixture may look runnier than you’d like at this point, but don’t overcook or the caramel will get very hard as it cools.

Assembly

1. Mix the granulated sugar and cinnamon in a medium bowl. Lightly brush the tube pan with butter, making sure you butter the centre portion thoroughly. Sprinkle with sanding sugar, tapping out any excess; set aside. Remove the dough from the freezer and peel back the plastic. Brush the entire surface with melted butter and sprinkle generously with some cinnamon sugar. Shake excess sugar back into the bowl.
2. Invert the baking pan and turn out the dough onto a work surface, sugar side down. Remove the plastic and discard. Brush the other side of the dough with butter and sprinkle with more cinnamon sugar. Use a bench scraper, a pizza cutter or a chef’s knife to cut the dough into a 12×6 grid.
3. Working relatively quickly so the dough doesn’t become too soft, separate the pieces. Working one at a time, roll them lightly between your palms into balls, dusting with more cinnamon sugar as needed to prevent sticking. Place in the prepared tube pan as you go. Cover the pan with plastic wrap and let sit in a warm, draft-free spot until the pieces have swelled to nearly doubled in size (40–50 minutes).
4. Preheat the oven to 350°F a little before the monkey bread is ready to bake.
5. Remove the plastic from the pan and bake the monkey bread until golden brown (25–35 minutes). Let cool 10 minutes, then use a small offset spatula to loosen the monkey bread from the sides of the pan. Pull the bottom out from the pan and use the spatula to loosen the bread from the bottom. Slide the bread back into the pan; invert onto a plate and remove the pan. Place a wire rack over the bread and invert right side up onto rack. If using a Bundt pan, just invert directly onto wire rack. Let cool at least 15 minutes before serving.
6. Pour about ½ cup caramel sauce over the monkey bread if desired. Serve with more sauce alongside for dipping.