Masonry Heaters are often built with an accompanying bakeoven. There are two types of bakeovens, black and white. A white bakeoven is heated from the main firebox indirectly. What this means is there is no ash on your food, however, it also means you do not have the option of building a small fire in the bakeoven to bring it up to temperature if you need a slightly higher temperature. A black oven is just that, black. It gains much of it’s heat from the main firebox but you can, if you wish build a smaller fire within the bakeoven to raise the temperature. People who want the cheese on their pizza melted perfectly often choose a black bakeoven as it allows you the option of raising the ceiling temperature that last little bit to get perfectly melted cheese. Again, it should be noted that this is a personal preference for the style of baking you will be doing. A secondary option for those who want a clean pizza bottom is that you can fire the oven and insert a clean baking stone for your pizza.
If you are thinking of adding a black bakeoven to your Masonry Heater build you might want to think long-term. In the long-term you will find that the flames and heat of the main firebox can damage the open throat of the black bakeoven. Ideally, you would choose a throat that has easily repairable and replaceable parts. This is a similar consideration when looking at various masonry heater fireboxes. Ones build with a standard firebrick will be more easily repaired in 100 years than ones built out of a cast in place or a-typical brick size or shapes.