In microwave dish combine all the chocolate chips and ¾ cup of the cream. Cook on high for 1 to 2 minutes, stirring every 30 seconds until smooth, whisking well at the end. Cool to room temperature, about 15 minutes. Stir in sugar & vanilla.In separate bowl, beat the rest of the cream until soft peaks form. Beat in chocolate mixture on high speed ⅓ at a time. Mix well and pour into crust.