In small saucepan, stir chocolate and 1/2 cup cream over medium just until chocolate is melted. Let cool to lukewarm. In large bowl, using electric mixer, beat remaining 1 cup cream, 2 tsp. zest, and 2 tbsp. juice until stiff peaks form. Fold in chocolate mixture. Spoon mousse into 6 small (about 6 oz.) ramekins. Chill until set, 4 hours orovernight. In medium bowl, toss raspberries, sugar, and remaining 2 tsp. zest and 3 tbsp. juice. Spoon over mousse.
The Do's and Don'ts of Cooking with Chocolate