I do a spice ale that has cinnamon, nutmeg, allspice and cloves in varying amounts. I usually grind up whatever spice I am going to use and add it in the secondary. I sort of feel like I want to feature the spices in this recipe, so I wait until there is no troub to absorb flavor and no fermentation to outgas aroma. One ground up stick of cinnamon goes a long way, although I like to go with 2 for my spice beer. Slightly off topic... The last time I did this, I figured I'd just add the ground spices to the keg. The spices ended up jamming the outflow tube/poppit and I spent a lot of time over the next couple weeks dismantling and cleaning the posts so I could get beer out. Lesson learned, stick with a secondary.