Cover the cashews with water and soak for at least 2 hours.
Line a 24cm x 32cm deep tray with baking paper. To make the honeycomb, heat the sugar and honey in a saucepan over low heat until dissolved. Increase to a moderate heat and cook until it turns a golden caramel colour. This won't take long but is essential to ensure any moisture in the honey has evaporated, ensuring a crunchy honeycomb.
Remove from heat, stir in bicarbonate soda (it will expand and foam), and immediately pour into the tray. Let set for 1–1.5 hours to harden.
Drain the cashews and blend with the coconut cream, honey, and matcha until smooth. Pour into moulds and freeze for at least 4 hours or until set firm.
Melt the white chocolate in 20-second microwave bursts, stirring in between. Finely crumble the honeycomb into coarse crumbs and mix into the melted chocolate. Dip the frozen ice creams into the chocolate, then return to the freezer until set.