In a small bowl, combine the packed light brown sugar, ground cinnamon, and 3 tablespoons of melted butter. Mix well until a thick paste forms. Set aside.

In another small bowl, whisk the softened cream cheese until smooth. Gradually add the powdered sugar, milk (starting with 1 tablespoon and adding more as needed for desired consistency), and vanilla extract. Whisk until the glaze is smooth and pourable. Set aside.

In a large mixing bowl, whisk together the all-purpose flour, granulated sugar, baking powder, and salt.

In a separate medium bowl, whisk together the milk, eggs, 1/3 cup melted and cooled butter, and vanilla extract.

Pour the wet ingredients into the dry ingredients. Stir with a rubber spatula until just combined. A few lumps are fine; do not overmix, as this can make the waffles tough.

Preheat your waffle iron according to the manufacturer's instructions. Lightly grease the waffle plates with cooking spray or butter, if necessary.

Pour approximately 1/2 cup of waffle batter onto the center of the hot waffle iron (adjust amount based on your waffle iron size).

Immediately drizzle about 1-2 tablespoons of the cinnamon swirl mixture evenly over the batter. You can use a knife or a skewer to gently swirl it into the batter for a more marbled effect.

Close the waffle iron and cook for 3-5 minutes, or until the waffle is golden brown and crispy, and steaming stops.

Carefully remove the cooked waffle from the iron. Repeat with the remaining batter and cinnamon swirl mixture.

Serve the cinnamon roll waffles warm, drizzled generously with the prepared cream cheese glaze.