Today I tried out the bagel recipe in How to Be a Domestic Goddess and it worked wonderfully. I was wondering how I could use this basic recipe to make cinnamon raisin, blueberry or Parmesan and dried tomato bagels. Do I just add the extra ingredients once the dough had its first rise or do I have to adjust quantities of the recipe?
When adjusting existing recipes you need to consider how the additional or changed ingredients will affect the overall mixture. Fortunately adding dried fruits and nuts to bread doughs is fairly simple as the addition of these ingredients doesn't usually affect the basic dough recipe. Once the dough has had its first rise, knock it back then flatten the dough out and sprinkle over the fruit and /or nuts. Knead these ingredients in then shape the bagels as directed in the recipe. The advantage of adding the ingredients at this point is that you can generally judge by eye how much you need, but be careful not to overload the dough too much with additional ingredients. If you would like a guideline then we would suggest using about 250g raisins or other mix-ins for Nigella's recipe (which uses 1kg/6 2/3 cups flour).
If adding spices such as cinnamon then you need to do this at the mixing stage. The quantity needed will depend on your own taste but as a guideline use 2-3 teaspoons ground cinnamon for Nigella's recipe. We would be slightly cautious on adding Parmesan to the dough as the cheese can affect the consistency and make the bagels slightly greasy. It may be better to sprinkle some Parmesan on the bagels just before the baking stage. If using sun dried tomatoes that have been packed in oil then make sure to blot the tomatoes thoroughly with kitchen roll (paper towels) as the oil from the tomatoes could slow down the dough on the second rise.