Preheat oven to 350 degrees F (175 degrees C).

Combine dates, avocado, 1/2 cup maple syrup, and 1/2 cup coconut oil in a blender; blend until smooth.

Mix cocoa powder, oat flour, baking powder, and salt together in a bowl. Add date mixture to the flour mixture; mix until well combined. Spread into a baking dish.

Bake in the preheated oven until top is dry and edges have started to pull away from the sides of the pan, about 20 minutes. Let cool, about 20 minutes.

Mix cocoa powder, 2 tablespoons coconut oil, and 2 tablespoons maple syrup in a bowl to make icing. Pour over cooled brownies.