1. Heat oven to 400°F. Whisk together baking mix, sugar and cocoa in large bowl, breaking up lumps to blend. Add milk and butter, stirring just until combined. Add chocolate chips, mixing to distribute evenly.
2. Divide dough into 8 equal portions. Place on ungreased cookie sheet, spacing 2 inches apart. Flatten each portion to about 3/4-inch thickness.
3. Bake 12 to 15 minutes until springy to the touch. Remove from baking sheet to wire rack. Cool slightly.
4. Place each shortcake on an individual plate. Spoon strawberries over shortcakes; top with whipped cream. Spoon additional berries over whipped cream and sprinkle with blueberries, if desired. 8 servings.
SWEETENED WHIPPED CREAM: Combine 1 cup (1/2 pt.) cold whipping cream, 2 tablespoons sugar and 1/2 teaspoon vanilla extract in medium bowl; beat until soft peaks form. About 2 cups whipped cream.
* Sliced strawberries may be sweetened, if desired, by adding 2 to 3 tablespoons sugar to berries while shortcakes are baking.