Mix 1 teaspoon water with 1 teaspoon cornstarch in a small bowl. Set aside. Combine raspberries, granulated sugar, and remaining water in a saucepan over medium heat. Stir, breaking up raspberries. Once simmering, add cornstarch mixture. Continue to simmer for 3 minutes. Remove from heat and strain. Cool completely.

Preheat oven to 350°F (177°C). Line a 9-inch square baking pan with parchment paper.

Pulse 22 Oreos in a food processor into fine crumbs. Combine crumbs with melted butter and press into the bottom of the prepared pan. Bake for 8 minutes.

Melt white chocolate in a double boiler or microwave until smooth. Let cool.

Beat cream cheese and sugar until smooth. Add flour, lemon juice, vanilla, and salt; beat until combined. Add eggs, one at a time, beating after each addition. Stir in melted white chocolate.

Pour half of the cheesecake filling onto the crust. Drizzle half of the raspberry sauce on top. Spread remaining filling, drizzle with remaining sauce, and swirl together.

Bake for 32-36 minutes until set. Cool for 45 minutes at room temperature, then refrigerate for at least 3 hours before slicing.

Lift bars out of the pan using parchment overhang and cut into squares. Store leftovers in the refrigerator for up to 1 week.