A few of my baker friends have been asking me how I get "the boom" in my panettone, namely its fluffy strands and consistency. Honestly, for me it's been a matter of experimentation. Where I've found success is focusing on the details; fermentation, temperatures, and mixing. For instance, adding sugar at the right time so you don't slow down wild yeast, that making for cakey rather then airy final product. Once that's covered you can start thinking about added flavors.