
1. Preheat oven to 375°F. Lightly coat an 8-inch square baking dish with cooking spray. Melt butter in a small skillet over medium. Continue cooking, stirring constantly, until butter is browned and has a nutty aroma, 2-3 minutes. Pour butter into a large bowl; stir in cinnamon and nutmeg. Let cool for 5 minutes.
2. Stir together oats, baking powder, salt, and pecans in a medium bowl; set aside. Add milk, maple syrup, egg, and vanilla to cooled butter mixture; whisk to combine. Stir in the oat mixture.
3. Arrange bananas in a single layer on bottom of prepared baking dish. Sprinkle evenly with ¾ cup of the raspberries. Spoon oat mixture evenly over top. Sprinkle with remaining ¾ cup raspberries, then with coconut, and finally, garnish with a sprinkling of pecans. Bake until set and golden brown, about 35 minutes. Let cool 5 minutes.