Heat a non-stick skillet to medium heat and drizzle with olive oil. Add the bell peppers, onions, salt and pepper. Stir to combine and cook until the onions are translucent.
Add the garlic and cook for another minute. Add the harissa and stir to combine everything. Then add the tomato and stir to combine. Cook for 20 minutes until the sauce thickens. Transfer to a plate and set aside.
In a large bowl, whisk together the flour, sugar, baking powder, and salt until well combined. Set aside.
In a separate bowl, whisk together the milk, vegetable oil, eggs, and vanilla extract.
Pour the wet ingredients into the dry ingredients and whisk until just combined. Don’t overmix, some lumps in the batter are okay.
Heat The Stuffed Waffle Iron to medium heat and brush with a little olive oil. Pour ⅓ cup of the batter into the bottom waffle pan to cover the waffle grids.
Add the shakshuka filling and an egg.
Cover with more waffle batter to fill to the rim of the bottom pan. Close The Stuffed Waffle Iron and flip. Reduce the heat to medium-low. Cook for 6 minutes on each side.
Remove the waffle using the inserted thongs. Serve immediately.