Pulse pretzels in a food processor until fine crumbs form. Add 2 tablespoons granulated sugar and melted butter; pulse just until combined. Divide mixture among 6 half-pint canning jars or dessert dishes., For cheesecake layer, beat cream until stiff peaks form. In another bowl, beat cream cheese, confectioners' sugar and vanilla until smooth. Fold in 1-1/2 cups of the whipped cream, then baking chips. Spoon over pretzel mixture. Refrigerate, covered, until cold, about 3 hours., Meanwhile, in a clean food processor, puree 1-1/2 cups blackberries with remaining sugar; remove to a bowl. Cover and refrigerate berry mixture and remaining whipped cream until serving., To serve, top with blackberry mixture, reserved whipped cream and additional blackberries.