NOTE: i am looking for technique help, NOT a recipe.
i love making these as they are fast, versatile, do-ahead and a relatively light yet not overly sweet finish to a meal. my usual starting point is the joy of baking almond sponge roll.
today i fell down an internetz rabbit hole and found this sort of thing^^^
i found 2 techniques, one of which requires freezing each colored part separately to complete the design then layering the batter over. the 2nd calls for par-baking each colored bit for 1-2 minutes. anybody have satisfactory experience with this? seems like you'd have bits either under- or overcooked? is it a better visual that i should just skip in favor of superior texture and taste?
lastly, how different is the end product from the japanese sponge cake recipes vs. the french/italian versions with which i am more familiar?