1.Make orange jelly: combine juice and marmalade in small saucepan, bring to the boil; remove from heat. Add jelly crystals, stir until dissolved; cool. Line a deep 23cm (9¼ inch) square cake pan with baking paper, extending paper 5cm (2 inches) above edges of pan. Pour jelly into pan; refrigerate until set.
2.Preheat oven to 180°C/350°F. Grease oven trays; line with baking paper.
3.Spread sugar evenly over base of shallow oven tray; heat in oven until sugar feels hot to touch. Beat eggs in small bowl with electric mixer on high speed for 1 minute; add hot sugar, beat about 10 minutes or until mixture is thick and will hold its shape.
4.Meanwhile, sift flour three times. Fit large piping bag with plain 1cm (½ inch) tube.
5.Transfer egg mixture to large bowl; fold in sifted flour. Place mixture into piping bag. Pipe 4cm (1½ inch) rounds of mixture onto oven trays, about 3cm (1¼ inches) apart. Sprinkle each round evenly with extra sugar. Bake each tray, one at a time, about 4 minutes. Cool on trays.
6.Lift jelly from pan to board. Using a 4cm (1½ inch) round cutter, cut out 25 shapes.
7.Top each sponge with a round of jelly, place on wire rack over tray; coat with chocolate. When chocolate is almost set, top with glacé orange wedges.
Store unfilled biscuits in an airtight container for up to a week. Store filled biscuits in an airtight container, in the refrigerator, for up to 3 days.Note