Melt the butter or coconut oil in a saucepan over medium heat.
Add the oats and toast for about 2 to 3 minutes, stirring often, until fragrant.
Add the salt and cinnamon.
Turn the heat to low and carefully pour in the water and milk, stirring.
Add the mashed banana, if using.
Cover and cook for 5 minutes until tender, then remove from the heat.
Serve immediately for a chunky texture, or stir in an additional ½ cup milk for a creamier body.
Top with the peanut butter and any other toppings as desired.
