- Chocolate Mousse: In bowl of stand mixer, stir together chocolate mousse mix and milk. Scrape down sides and bottom of bowl. Using whip attachment, mix at low speed for 1 minute. Scrape down sides and bottom of bowl. Cover the mixer. Whip at high speed for 5 to 6 minutes or until peaks form.
- Tiramisu Mousse: In another stand mixer bowl, stir together tiramisu mousse mix and milk. Scrape down sides and bottom of bowl. Using whip attachment, mix at low speed for 1 minute. Scrape down sides and bottom of bowl. Cover the mixer. Whip at high speed for 5 to 6 minutes or until peaks form.
- Assembly: Arrange half the shortcake cookies in a single layer in full hotel pan. Pour half the cold coffee evenly over cookies. Let stand for 5 minutes. Spoon chocolate mousse over cookies; smooth top. Layer on remaining cookies. Pour remaining coffee evenly over cookies. Let stand for 5 minutes. Spoon tiramisu mousse over cookies; smooth top. Spoon whipped topping over tiramisu mousse; smooth top. Sprinkle with chocolate chips. Refrigerate for at least 4 hours before serving.
- Scoop into twenty-five 270 mL (1 cup) servings.
Tips: Substitute chocolate chips with crushed chocolate cookie crumbs or shaved chocolate. Substitute shortcake cookies with shortbread cookies if preferred.
