In a large mixing bowl, combine the all-purpose flour, baking powder, granulated sugar, brown sugar, salt, and ground cinnamon. Whisk until well combined.
Add the room temperature unsalted butter, eggnog, and large eggs to the dry ingredients. Mix until a soft dough forms. If the dough is too sticky, sprinkle in a little additional flour as needed.
Flour your work surface lightly and transfer the dough onto it. Using a rolling pin, roll the dough into a rectangle about ½ inch thick.
Brush the rolled-out dough with the melted butter (3 tablespoons). In a small bowl, mix the brown sugar and cinnamon, then sprinkle it evenly over the buttered dough.
Starting from one long edge, carefully roll the dough into a tight log. Pinch the seam to seal it.
Using a sharp knife or a bench scraper, cut the rolled dough into 12 equal pieces. Place them in a greased baking dish, cut side up.
Preheat your oven to 350°F (175°C). Bake the cinnamon rolls for 25-30 minutes, or until they are lightly golden on top.
While the rolls are baking, prepare the glaze by whisking together the melted butter, powdered sugar, and eggnog in a small bowl until smooth.
Once the rolls have cooled slightly, drizzle the glaze over the top. Serve warm and enjoy the comforting flavors of the season!