01 - Combine bread flour, sourdough starter, water, and salt in a large bowl. Mix until a shaggy dough forms. Cover and let rest for 30 minutes.
02 - Perform 2 to 3 sets of stretch and folds over 1.5 hours, resting 30 minutes between each set. After the final fold, cover and refrigerate dough overnight for 8 to 12 hours.
03 - Generously oil a 9x13-inch baking pan. Transfer chilled dough to pan, stretching gently to fit. Cover and let rise at room temperature for 2 to 3 hours until very puffy.
04 - Beat cream cheese, sugar, egg yolk, vanilla extract, and lemon zest in a medium bowl until completely smooth and creamy. Set aside.
05 - Toss fresh raspberries with granulated sugar and lemon juice in a small bowl. Let stand to release juices.
06 - Preheat oven to 425°F.
07 - Dimple the risen focaccia dough with oiled fingers. Drop cheesecake mixture in dollops across the surface. Gently swirl with a knife or spatula to distribute. Scatter raspberries and their juices evenly over the top.
08 - Drizzle additional olive oil over the surface. Bake for 25 to 30 minutes until golden brown, set in the center, and edges are crisp.
09 - Let cool in pan for at least 30 minutes before slicing. Serve warm or at room temperature for best texture and flavor.