Preheat oven to 375 degrees. In a large mixing bowl, whisk together oats, milk, eggs, maple syrup, vanilla, chia seeds, oil or butter, baking powder and seasonings until well combined.
Stir in carrots and raisins, making sure carrots are evenly distributed. Pour mixture into a greased 8×8 baking pan and bake for 40-45 minutes, or until top is lightly golden and oats are set.
In a mixing bowl, combine frosting ingredients and whisk well. To make extra smooth, a hand or stand mixer works well. Place frosting in the fridge to firm up while oats bake.
