In a medium saucepan, combine 1 cup of pomegranate juice and 1/2 cup of sugar over medium heat. Stir continuously until the sugar fully dissolves, then sprinkle 1 tablespoon of gelatin powder over the mixture and stir until dissolved. Remove from heat and allow it to cool slightly. Gently fold in 1 1/2 cups of whipped heavy cream until just combined.

Preheat your oven to 350°F (175°C). In a large mixing bowl, whisk together 3 eggs and 1/3 cup of sugar until pale and fluffy, about 5 minutes. Slowly fold in 1/4 cup of melted butter and 1 teaspoon of vanilla extract. Sift in 1 cup of flour and gently combine until no flour streaks remain. Pour the batter into a lined dome mold and bake for 20 minutes or until golden and a toothpick inserted comes out clean. Let cool completely.

Once the sponge cake is cool, carefully cut out the cake domes and place them into the same dome mold. Pour the pomegranate mousse evenly over each sponge base, filling to the top. Cover the mold with plastic wrap and place it in the freezer for at least 4 hours, or until the mousse is firm and set.

In a saucepan, combine 1/2 cup of pomegranate juice, 1/3 cup of sugar, 1 tablespoon of gelatin, and 1/4 cup of corn syrup over medium heat. Stir until the gelatin and sugar dissolve completely. Remove from heat and mix in 4 ounces of chopped white chocolate until smooth. Allow the glaze to cool to 90–95°F (32–35°C) before pouring over the frozen mousse domes.

Remove the frozen mousse domes carefully from the mold, placing them on a wire rack. Slowly pour the cooled mirror glaze over each dome, ensuring they are evenly coated. Allow the glaze to set for about 30 minutes at room temperature before transferring them to the refrigerator to chill until serving.

Keeping the domes chilled, carefully transfer them to a serving platter. For an added touch, garnish with fresh pomegranate seeds and a dollop of whipped cream. The Glossy Pomegranate Mousse Domes are now ready to impress your guests.