Mix gelatin and cold water in a bowl until softened; stir in boiling water until gelatin is dissolved.

Beat orange juice and eggs together in a bowl using an electric mixer until combined. Beat sugar and orange liqueur into the orange juice mixture; add gelatin mixture and stir until smooth.

Beat cream in a separate bowl using an electric mixer until soft peaks form. Lift your beater or whisk straight up: whipped cream will form soft mounds rather than a sharp peak. Carefully fold whipped cream into orange juice-gelatin mixture until just combined; pour into a glass trifle dish. Freeze until set, 8 hours to overnight. Thaw before serving.