Spray an 8x8 pan with nonstick cooking spray or coat lightly with coconut oil.
Add sugar, milk, butter, and cocoa powder to a medium heavy-bottomed saucepan over medium-high heat. Bring to a boil for about three minutes. Remove from heat and stir in Nutella or peanut butter, vanilla, salt, oats and coconut. Pour batter into prepared pan and spread evenly. Allow to dry for about 15 - 20 minutes until firm.