Line a 2lb loaf tin with cling film, leaving overhang on all sides.
In a large bowl, use an electric hand mixer to beat the yoghurt, icing sugar, and lemon zest together until well combined.
Reduce to a slower speed and gradually add the double cream. Increase speed as it thickens, mixing until medium peaks have formed.
Transfer two-thirds of the yoghurt mixture to another large bowl and fold in ½ jar of the lemon curd. Cover the remaining yoghurt mixture and refrigerate to use later to decorate the sides.
Place a single layer of Rich Tea biscuits over bottom of the prepared tin, breaking pieces to fit. Use a spatula to evenly spread a quarter of the yoghurt mixture over the biscuits.
Spread ½ jar of the blueberry preserve on top, then carefully spread another layer of the yoghurt mixture.
Spread a thin layer of the lemon curd on top of this.
Spoon a third of remaining yoghurt mixture over this and top with another layer of biscuits.
Repeat the layering process until the tin is full allowing space to finish with a layer of yoghurt mixture and then finally, the biscuits.
Cover with cling film and freeze for a minimum of 6 hours.
To finish the cake, take it out of the freezer and remove from the tin using the cling film to help. Upturn it onto a board or serving plate and then spread the top and sides of the cake with the refrigerated yoghurt mixture. Return it to the freezer for 20 minutes.
Make a compote by adding 4 tbsp of Blueberry Preserve to a non-stick pan with 2 tbsp water, 2 tbsp caster sugar and the fresh blueberries. Gently simmer on a low heat for 5 minutes until the fruit breaks down, adding more water if required. Remove from the heat and allow to cool slightly.
Serve slices of the cake drizzled with the blueberry compote.