1 1/2 cups heavy whipping cream
3/4 cup sugar
1/2 cup cold water
1 1/2 teaspoons unflavored gelatin
8 ounces sour cream
2 teaspoons vanilla extract
Raspberry Sauce
3 cups fresh raspberries
1/3 cup sugar
1 teaspoon cornstarch
1 teaspoon lemon juice

In small, heavy saucepan, combine cream and sugar. Stir over medium heat till sugar dissolves. Remove from heat. In another small saucepan, combine water and gelatin. Let stand 5 minutes to soften. Stir over medium heat till gelatin dissolves. Stir into cream mixture and mix well. Cover and chill 45 minutes till mixture thickens to yogurt consistency. Spoon 1/4 cup of cream into bottom of each of 6 serving glasses. Drizzle 2 tablespoons sauce over cream. Spoon another 1/4 cup of cream over the top. Drizzle with remaining sauce and marble by swirling with knife. Cover and chill 2-4 hours. Top with fresh berries before serving.
Raspberry Sauce
Puree 1 1/2 cups berries. Press through fine mesh sieve to remove seeds. Repeat with remaining berries. This should yield 1 cup of puree. Stir together sugar and cornstarch in small saucepan. Add puree and lemon juice. Cook and stir over medium heat till thick and bubbly. Cook and stir 2 minutes longer. Remove from heat and cool.