Cook the Bacon: Heat a large skillet over medium heat and cook the bacon for about 3 minutes on each side until it becomes crispy and golden brown. Remove the bacon and place it on a plate lined with paper towels to cool. Once cooled, chop the bacon into small pieces and set aside.
Start the Oatmeal Base: In a large Dutch oven or soup pot, melt 4 tablespoons of butter over medium-high heat. Add the water, milk, oats, and ¼ teaspoon of salt. Stir occasionally as the mixture comes to a boil. Once boiling, reduce the heat to low and let it simmer, uncovered, for about 8 minutes.
Add Flavorings: Stir the maple syrup, vanilla extract, ground cinnamon, and nutmeg into the oatmeal. Continue cooking for 3 more minutes, allowing the flavors to blend together. Then, remove the pot from the heat.
Finish the Oatmeal: Add the remaining 2 tablespoons of butter to the oatmeal in small pieces, stirring them in until melted. Cover the pot and let the oatmeal rest for about 5 minutes to thicken. Taste and adjust the seasoning by adding more salt or cinnamon if needed.
Assemble and Serve: Divide the oatmeal into serving bowls and sprinkle the crispy bacon pieces on top. Drizzle with extra maple syrup for sweetness, and if desired, add your favorite toppings, such as fresh fruit or toasted nuts. Serve warm and enjoy!