Prepare the Dough: In a large mixing bowl, combine the flour, sugar, instant yeast, and salt. Add the warmed milk, melted butter, and eggs. Mix until a soft dough forms.
Knead the Dough: Transfer the dough onto a floured surface and knead for about 5 minutes until smooth. Place in a greased bowl, cover with plastic wrap, and let it rise for 1 hour or until doubled in size.
Make the Filling: In a bowl, mix the softened butter, brown sugar, and cinnamon until well combined. Set aside.
Assemble the Rolls: Once the dough has risen, punch it down and roll it out into a rectangle (about 16x12 inches). Spread the cinnamon filling evenly over the dough.
Roll and Slice: Starting from the long edge, roll the dough tightly into a log. Slice into 12 equal pieces and place them in a greased 9x13-inch baking dish.
Overnight Rest: Cover the dish with plastic wrap and refrigerate overnight.
Bake the Rolls: Preheat the oven to 350°F (175°C). Remove the rolls from the fridge and let them sit at room temperature for 30 minutes. Bake for 25-30 minutes or until golden brown.
Make the Icing: While the rolls are baking, whisk together the powdered sugar, milk, and vanilla extract until smooth.
Serve: Drizzle the icing over the warm cinnamon rolls and enjoy!