For the orange rum mousse: Combine the eggs, yolks, granulated sugar, orange zest, ginger and salt in a medium saucepan. Whisk until light and smooth. Whisk in the orange juice, lemon juice and butter over medium-low heat. Whisk constantly until the butter melts. Continue to whisk until the mixture thickens, 5 to 6 minutes. Strain through a fine mesh sieve into a large bowl. Cover the surface with plastic wrap and refrigerate until chilled, about 2 hours.
For the panettone: Preheat the oven to 325 degrees F. Spread the panettone cubes on a baking sheet and bake until lightly toasted but still soft inside, 8 to 10 minutes. Let cool.
Once the orange mixture is chilled, whip the cream with an electric hand mixer in a large bowl. Add the confectioners' sugar and whisk on high speed to soft peaks. Add the spiced rum and vanilla and mix just to combine.
Add about 1/3 of the cream to the chilled orange mixture and stir in to lighten it. Add the remaining cream and gently fold it in.
To assemble the trifle: Spread a third of the panettone cubes in the bottom of a trifle dish. Top with half of the strawberries, facing them outwards against the glass of the trifle dish. Spread a third of the cream mixture over top. Top with another third of the panettone cubes and the remaining strawberries. Spread with another third of the cream. Top with the final layer of panettone. Spread with the remaining cream and smooth the top. Refrigerate until well chilled, at least 3 hours or overnight.