Put the bananas in a bowl with the lemon juice and mash until smooth. Stir in the honey, followed by the yogurt and nuts, and beat well. Place the banana mix and the cream in an ice-cream machine. Churn and freeze following the manufacturer's instructions until half frozen. Alternatively, whisk the cream until it forms soft swirls, then fold into the banana mix and freeze in a plastic container for 3–4 hours until partially frozen.
Whisk the egg whites lightly until they form soft peaks. Add to the ice-cream machine and continue to churn and freeze until completely frozen. Alternatively, break up the ice cream in the plastic container with a fork, then fold in the whisked egg white and freeze until firm.
Make the praline. Pour the measured water into a heavy saucepan and add the sugar and golden syrup. Simmer gently until the sugar has dissolved, then cook to a caramel-coloured syrup. Place the toasted almonds on a lightly greased piece of foil and pour the syrup over. Leave to set for 1 hour. Once set, break up into irregular pieces and serve with the ice cream.