as for adding flavors, I would add any dry ingrediants (spices, vanilla beans, instant espresso powder), extracts or flavor compounds towards the end of the final whipping process. I feel the natural oil in spices breaks down the marshmallow and makes it a little too soft. Also, you can make a honey flavored marshmallow using a similar recipe 240 g whites 20 g gelatin 360 g sugar 40 g honey. I would caramelize the honey to intensify the flavor. Add the sugar, cook with water to 155 C. pour into whipping soft peak whites You can substitute fruit purees for water. I've made great raspberry flavored ones.
