Add all the ingredients for the sabayon into a heatproof bowl and began beating with an electric mixer. Meanwhile, bring a pot of water to a boil. The water level should be low enough so that it doesn't touch the bottom of the bowl. Once water is boiling, turn to lowest heat to reduce to a very gentle simmer. Place the bowl on top and continue beating for 6~10 minutes until mixture is thick and fluffy.
If you have an instant thermometer, remove mixture from heat when it registers between 165ºF and 170ºF. You can get close enough without one by gauging the time, warmth, and texture of the batter. Place on top of a cold towel or ice bath to stop the cooking and let cool.
Add mascarpone into a clean mixing bowl and fold in the sabayon. Do not scrape the sides of the bowl used to make the sabayon since there's cooked egg stuck to it, be cautious when scooping out the mixture.
Whip the heavy cream (or egg whites if you're using) to medium peaks, adding the sugar halfway. Fold in to the mascarpone mixture along with the orange zest.
Whisk hojicha in 70ml of the hot water (do not use boiling water to avoid bitterness). Add to a long container (long enough to fit the ladyfingers), then add the maple syrup and the rest of the hot water. Mix well so the syrup incorporates.
Quickly dip the ladyfingers into the hojicha mixture and being layering them in your pan. You want to fully coat the ladyfingers but be fast since they get soggy easily. If they don't fit perfectly you can just cut them (save the cut off bits to make tiny versions in smaller containers if you have enough of the mascarpone mixture leftover!)
For three layers, roughly split the mascarpone mixture into thirds and alternate layering with the ladyfingers (the last layer should be the last third of the mascarpone mixture).
Chill for at least 6 hours in the fridge. Top generously with cocoa powder before serving.
