Puree the raspberries with 3/4 cup sugar and 1/3 cup water in a blender. Pour through a fine-mesh sieve into a bowl.

Bring half of the raspberry puree to a boil in a small saucepan over medium heat. Sprinkle 4 teaspoons gelatin over 1/2 cup cold water in a medium bowl; let stand 1 minute. Stir in the hot raspberry puree until the gelatin dissolves, then stir in the remaining raspberry puree.

Spray nine 5-ounce paper cups with cooking spray. Fill each cup about three-quarters full with the raspberry gelatin mixture. Refrigerate until the gelatin starts setting but the surface is still tacky, about 45 minutes.

Meanwhile, bring the half-and-half and the remaining 1/4 cup sugar to a boil in a small saucepan, stirring until the sugar dissolves. Add the chocolate, reduce the heat to low and cook, stirring, until smooth. Sprinkle the remaining 2 teaspoons gelatin over 1/2 cup cold water in a medium bowl; let stand 1 minute. Pour in the chocolate mixture and stir until the gelatin dissolves. Pour the chocolate gelatin mixture into the cups on top of the raspberry gelatin and refrigerate until fully set, about 3 hours.

Unmold the gelatin: Invert the cups onto plates and carefully tear off the paper. Top with whipped cream and raspberries.

Photograph by Jonathan Kantor