Lightly coat the inside of each souffle cup with the butter. Sprinkle the inside of each cup with 1 1/2 teaspoons granulated sugar. Set aside until needed. Heat 1-inch of water in the bottom half of a double boiler over medium heat. Place the semisweet and unsweetened chocolate in the top half of the double boiler. Tightly cover the top with plastic wrap. Heat for 6 to 8 minutes. Remove from the heat and stir until smooth. Transfer the chocolate to a large stainless steel bowl. Use a whisk to stir in the egg yolks and heavy cream until thoroughly combined. Set aside.
Place the egg whites on the bowl of an electric mixer fitted with a balloon whip. Whisk on high until soft peaks form, about 1 minute. Add the remaining sugar and continue to whisk on high until stiff peaks form, about 45 to 50 seconds. Remove the bowl from the mixer. Use a rubber spatula to fold about 1/4 of the whipped egg whites into the melted chocolate mixture, then fold in the remaining egg whites. Evenly divide the souffle mixture into the prepared souffle cups (about 4 heaping tablespoons), filling them to 1/2-inch below the rim of the cup. Evenly divide and sprinkle the cookie pieces and chocolate chips over the tops of the souffle mixture.
Place the souffles on the center shelf of the preheated oven. Bake until a toothpick inserted in the center comes out clean, about 22 to 26 minutes. Remove from the oven and serve immediately.