In a medium bowl, mix together 1 1/4 cups graham cracker crumbs and 1/4 cup butter, melted. Press mixture into the bottom of a lightly greased 9 inch springform pan.
In a medium saucepan, make the raspberry sauce by combining 1 12 oz. package frozen raspberries, 2 tablespoons sugar, 1 tablespoon cornstarch, and 1/2 cup water. Bring to boil, and continue boiling 5 minutes, or until sauce is thick. Strain sauce through a mesh strainer to remove seeds.
Place a baking pan filled with hot water on the lower rack of the oven. Preheat oven to 325 degrees. In a metal bowl over a pan of simmering water, melt 2 cups white chocolate chips with 1/2 cup Half and Half, stirring occasionally until smooth. Alternately, white chocolate can be melted in the microwave with the Half and Half in a glass bowl, at 50% power, stirring every 30-60 seconds until smooth.
In a large bowl, beat 3 8 oz. packages cream cheese and 1/2 cup sugar with an electric mixer until smooth. Blend in 1 tablespoon flour. With mixer on low speed, blend in 3 eggs one at a time. Blend in 1 teaspoon vanilla and melted white chocolate.
Pour half of batter over crust. Spoon 3 tablespoons raspberry sauce over batter. Pour remaining cheesecake batter into pan, and again spoon 3 tablespoons raspberry sauce over the top. Swirl batter with the tip of a knife to create a marbled effect.
Bake for 55 to 60 minutes, or until filling is set. Cool, cover with plastic wrap, and refrigerate for 8 hours before removing from pan. Serve with remaining raspberry sauce.