Preheat the oven to 150°C conventional (no fan). Line a loaf tin with baking paper.
Place the butter, honey and brown sugar in a saucepan over low heat. Stir continuously until the butter has melted and the mixture is smooth and well combined. Remove from the heat and leave to cool completely.
Once cooled, add the eggs one at a time, whisking vigorously after each addition until fully incorporated. Continue whisking until the mixture is smooth and well emulsified.
In a separate bowl, fork together the flour, cinnamon, salt, bicarbonate of soda and baking powder. Add the roughly chopped walnuts and toss them through the dry ingredients.
Pour the wet mixture into the dry ingredients and gently fold together with a wooden spoon until slightly combined.
Mash the ripe bananas into a smooth purée, mix in the cream fresh, then gently stir them into the batter, mix just to evenly combined.
Take care not to overmix, as this can make the cake heavier and less tender.
Pour the batter into the prepared loaf tin and gently smooth the top.
Bake in the preheated 150°C conventional oven for 50–60 minutes, or until the cake is well risen and a skewer inserted into the centre comes out without any raw batter or wet crumbs attached.
Allow the cake to cool in the tin for around 10–15 minutes before carefully lifting it out and transferring it to a wire rack to cool completely.