01 - Combine oats, milk, water, and salt in a medium saucepan. Bring to a gentle simmer over medium heat, stirring occasionally to prevent sticking.
02 - Once simmering, add raisins, cinnamon, and nutmeg. Reduce heat to low and cook, stirring frequently, until oats are creamy and thickened, about 10–12 minutes.
03 - Stir in maple syrup (or honey), vanilla extract, and butter. Mix well until fully incorporated and the oatmeal becomes silky and smooth.
04 - Spoon oatmeal into serving bowls. Top with a dollop of Greek yogurt or whipped cream for a cloud-like finish. Add toasted nuts and an extra drizzle of maple syrup if desired. Serve warm.