Preheat the oven to 160°C. Spray an 18 cm springform tin with olive oil and line the base with baking paper. Combine all the ingredients, except the berries, in a food processor and process until smooth. Spoon half the mixture into the prepared tin, then sprinkle the berries over the top and lightly swirl through. Finish with the remaining ricotta mixture and smooth the top of the cake. Bake for 30 to 35 minutes or until just set. Turn the oven off and allow the cake to cool in the oven for 1 hour. Remove and cool completely before serving. If you’re not eating the cake as soon as it has cooled, refrigerate until ready to serve. Garnish with extra berries and lightly dust with icing sugar if you like.