Preheat the oven to 350 degrees Fahrenheit (175 degrees Celsius). Spray an 11x7 inch non-stick baking dish with cooking spray and set aside.
In a saucepan, combine the Medjool dates with 1 cup of water. Bring to a boil over medium heat, and simmer for about 5 minutes until the dates are tender. Mash the dates until they form a smooth paste. Stir in the baking soda, and let it cool for about 10 minutes.
10 Medjool dates + 1 cup water, 1 teaspoon baking soda
In a large mixing bowl, combine the mashed bananas, rolled oats, cinnamon, nutmeg, salt, milk, egg, vanilla extract, and the prepared date paste. Mix until well combined.
2 cups old-fashioned rolled oats, 1/2 teaspoon cinnamon, 1/2 teaspoon nutmeg, 1/2 teaspoon salt, 2 cups milk of choice, 3 ripe bananas, 1 large egg, 1 teaspoon vanilla extract
Pour the mixture into the prepared baking dish, and spread it out evenly. Sprinkle the dark chocolate chips and chopped walnuts over the top.
1/2 cup dark chocolate chips, 1/4 cup chopped walnuts
Bake in the preheated oven for 25-30 minutes or until the oatmeal is set and the top is golden brown.
Remove from the oven, and let it cool slightly before slicing into squares.
Serve warm with toppings of choice as additional sliced bananas, a drizzle of maple syrup, or a dollop of yogurt. Enjoy the delicious and nutritious banana date oatmeal bake!