In a small saucepan over medium heat, add the milk, butter, and brown sugar. Stir until butter melts.
Add the salt, vanilla extract, and cinnamon. Let the mixture heat until small bubbles form around the edges.
Reduce heat to low and stir in the oats.
Cook for 5–7 minutes, stirring often, until the oats are tender and the oatmeal reaches your preferred consistency.
Remove from heat and serve in a bowl.
Top with a dusting of cinnamon or your favorite toppings like fruit, nuts, or more sugar if desired.