Preheat your oven to 160°C (320°F) and line a 9 × 9 inch (25 x 25 cm) square baking pan with parchment paper.
Crush digestive biscuits (or graham crackers) and mix with melted butter. Press firmly into the pan to form an even crust. Chill briefly in the fridge while you prepare the filling.
In a bowl, whisk cream cheese with sugar until smooth and creamy. Add yogurt and continue mixing.
Gradually add eggs, then stir in vanilla paste and the zest of 1 lemon. Mix until fully combined.
Pour the filling over the chilled crust. Drizzle raspberry sauce across the top and use a skewer to swirl it into a marbled pattern. Scatter 15-20 fresh raspberries on top.
Bake for 55-60 minutes until the edges are lightly golden and the centre still has a slight jiggle.
Cool completely at room temperature, then refrigerate for at least 1 hour before slicing into 12-16 bars. Chilling overnight gives the best texture.