Preheat the oven to 375°F (if you're using convection, reduce heat by 25°).
Combine the oats, nuts, baking powder, salt, and dried fruit in an 8x8 baking dish.
In a four cup measuring cup, whisk together the milk, water, egg, melted butter, and vanilla extract.
Pour the liquid over the ingredients in the baking dish. Place in the oven and bake for 45 to 50 minutes.
Eat hot, chilled or at room temperature.