Heat the oven to 160C/fan 140C/gas 3. Butter a 1.3 litre capacity ring tin (approx 20cm diameter) and dust the buttered surface with 1 tbsp each plain flour and caster sugar, then tap out the excess.
Beat the butter, sugar and honey with a hand-held electric whisk, until pale and fluffy with a dropping consistency. Beat in the eggs one at a time. Mix the flour, cornflour and poppy seeds and fold into the creamed mixture.
Spoon into the prepared tin and level the surface. Bake for about 35mins until risen and firm to the touch. Leave to cool slightly in the tin then carefully remove, easing the sides with a palette knife. Cool on a wire rack.
For the icing, mix both ingredients together then drizzle over the cake while it’s still on the rack and leave to set. Transfer to a plate to serve. Will keep in an airtight container in a cool place for up to 5 days.