By this time egg whites should be very fluffy. Turn mixer to lower speed and slowly pour in the hot agar agar mixture, then the lemon juice and the jell-o mixture. Turn mixer back to high and whip for additional 5 minutes.

Meanwhile prepare for piping the marshmallows - line an area of about 5-6 feet by 1.5 foot with plastic wrap or aluminum foil. Fit a 24 inch piping bag with a star tip (or use a ziplock bag with a snipped end). Fill the bag with marshmallow mixture, twist the open end and pipe out rosettes onto the plastic wrap lined table surface. Pipe them slightly bigger than you would want them in the end, as they shrink while drying. Dust the tops with powdered sugar generously. Leave the marshmallows on the table overnight to dry out the top surface. Next day, peel 2 halves off the plastic wrap and stick the two sticky sides together.