Preheat the oven to 375°F and spray an 8×8 square baking dish with cooking spray.
In a large bowl, mix together the oats, cocoa powder, baking powder, sea salt and flaxseed.
In the same bowl add almond milk, applesauce, coconut oil, maple syrup and peppermint extract. Stir together, then add chopped chocolate or chocolate chips.
Carefully pour oatmeal mixture into the prepared baking dish. Scatter additional chocolate on top, if desired.
Bake for 40-50 minutes, or until the oatmeal has set. Remove from the oven and immediately top with crushed candy canes. Let cool.
While baked oatmeal is cooling make icing by combining powdered sugar, vanilla extract and almond milk (start with 1 teaspoon) in a small bowl. Whisk until all lumps of sugar have dissolved and icing is the thickness you desire. You don't want it to be super thick, but also don't want it to be too runny.
Drizzle icing on top of baked oatmeal, portion and serve.