For the Dough:

1. Activate the Yeast: In a small bowl, combine warm milk and sugar. Sprinkle the yeast over the milk and let it sit for 5-10 minutes until frothy and bubbly.

2. Mix the Dough: In a large bowl, combine the flour and salt. Add the softened butter, eggs, and vanilla extract to the bowl. Pour in the yeast mixture and stir until a dough forms.

3. Knead the Dough: Transfer the dough to a floured surface and knead for about 5-7 minutes, until the dough is smooth and elastic.

4. Let the Dough Rise: Place the dough in a greased bowl, cover it with a clean towel or plastic wrap, and let it rise in a warm place for about 1 hour, or until it doubles in size.

For the Cinnamon Filling:

1. In a small bowl, mix the brown sugar and cinnamon together. Set aside.

To Assemble the Rolls:

1. Preheat the Oven: Preheat the oven to 350°F (175°C). Grease a 9×13-inch baking pan and set aside.

2. Roll the Dough: Once the dough has risen, punch it down and roll it out into a rectangle on a floured surface (about 12×18 inches).

3. Spread the Filling: Spread the softened butter evenly over the dough, then sprinkle the cinnamon sugar mixture over the top, making sure to cover the entire surface.

4. Shape the Rolls: Starting from one edge, carefully roll the dough tightly into a log. Slice the log into 12 even rolls and place them in the prepared baking pan.

5. Second Rise: Cover the rolls with a clean towel and let them rise for about 30 minutes until they puff up.

6. Bake the Rolls: Bake for 20-25 minutes, or until the rolls are golden brown on top and cooked through.

For the Glaze:

1. Make the Glaze: While the rolls are baking, whisk together the powdered sugar, milk, and vanilla extract until smooth. Add more milk if you want a thinner glaze.

Assemble and Serve:

1. Once the rolls are done baking, remove them from the oven and let them cool for a few minutes. Drizzle the glaze over the warm rolls and serve immediately.