In a medium saucepan, bring water and salt to a boil over high heat.
Stir in steel cut oats and reduce heat to low. Let simmer uncovered for 25-30 minutes, stirring occasionally, until oats are tender and have absorbed most of the liquid.
Remove from heat and stir in butter, brown sugar or maple syrup, vanilla extract, and cinnamon until well combined.
Let the oats rest for 2-3 minutes to thicken up a bit.
Divide into bowls and top each serving with a splash of milk. Add your favorite toppings like fresh berries, sliced bananas, or chopped nuts. Serve immediately while warm and cozy!