Rich chocolate mousse is made even more luscious with the addition of banana puree and grated coconut.
Peel bananas; cut into large pieces. Place in a saucepan with champagne and 1/4 cup sugar. Bring to a boil; reduce to a gentle simmer. Cook, partially covered, until very soft, 10 to 15 minutes. Transfer to the bowl of a food processor; blend until smooth. Set aside to cool. Chill until ready to serve, up to 6 hours ahead.
Place the chocolate in a heat-proof bowl set over a pan of gently simmering water. Stir until melted; set aside.
Place eggs and remaining 3/4 cup sugar in another heat-proof bowl; whisk until combined. Place over simmering water; whisk until warm. Remove bowl from heat, and whisk until the mixture is pale and thick. Whisk in the melted chocolate.
Place cream in a clean stainless-steel bowl, and whisk until stiff peaks form. Fold cream into chocolate mixture.
Place about 2 tablespoons of banana puree in individual serving dishes; top with a dollop (about 1/2 cup) of mousse. Refrigerate until ready to serve, up to 4 hours in advance. Garnish with coconut.