Heat oven to 160C/140C fan/gas 3. Butter and line the base of an 18cm Bundt mould or round cake tin (see p120) with baking parchment. Put the flour, cinnamon, butter, sugar, eggs and honey in a large mixing bowl and beat with a wooden spoon or hand-held electric mixer until light and fluffy.
Mash the bananas and chop the dates. Stir into the cake mix with the walnuts. Spoon into the prepared tin and smooth the top. Bake for 40-50 mins until firm to the touch and a skewer inserted into the centre comes out clean (a round tin may take 10-20 mins more). Cool in the tin for 15 mins, then turn out and cool on a wire rack.
To make the glaze, put the honey and butter in a small pan and bring to the boil, stirring until the butter has melted. Boil briefly, about 1 min, until slightly thickened. Remove from the heat and stir in the walnuts. Leave to cool until thickened and opaque. Spoon over the top of the cake and leave to set.