Puree the frozen berries and let stand to thaw while preparing the cake.
Process the cookies until it becomes finely ground. Add the melted butter, lemon extract, and peel and mix.
Press the crust into a standard springform pan. Bake at 175C for 10 minutes.
Meanwhile, put the cream cheese and starch into a bowl. Beat until smooth.
Add the whipping cream and sugar. Beat until the sugar granules start dissolving.
Add the eggs one at a time, beating until combined.
Divide the batter into two relatively equal halves (I just used the mixing bowl and a measuring cup so it would be easy to pour).
Add the berry puree to one half, and the lemon peel, extract, and juice to the other. Mix until combined.
Add the lemon batter to the pan. Pour (from a distance of about 20cm) the berry batter in stripes or a spiral pattern. Use a skewer and drag through the batter to make a spiderweb design.
Pop in the oven and bake at 150C for 60-70 minutes, until the center looks done and the edges just start to brown. Turn off the oven and leave at least an hour while the oven cools. Take out the cake and let stand to cool to room temperature before storing in the refridgerator.