Creating the delightful Black Forest Trifle for Christmas is straightforward when you follow these easy steps:

1. Bake the Chocolate Cake: Prepare the chocolate cake according to the box instructions. Allow it to cool completely.

2. Prepare the Cherries: Drain the Morello cherries, reserving the syrup. Divide the cherries into halves; set aside.

3. Make the Whipped Cream: In a large bowl, whip the heavy cream until it forms soft peaks. Gradually add the powdered sugar and vanilla extract, continuing to whip until medium peaks form.

4. Cube the Cake: Cut the cooled chocolate cake into bite-sized cubes, approximately 1-inch squares.

5. Assemble the Trifle: In a large glass trifle dish, begin layering. Start with a layer of chocolate cake cubes, then drizzle with cherry juice.

6. Add Cherries: Next, add a layer of halved cherries on top of the cake.

7. Add Whipped Cream: Spoon a generous layer of whipped cream over the cherries.

8. Repeat Layers: Repeat the layering process—cake, cherry juice, cherries, and whipped cream—until you reach the top of the trifle dish.

9. Finish With Whipped Cream: Top the final layer with whipped cream, creating a smooth dome.

10. Garnish: Add chocolate shavings and mint leaves to garnish.

11. Chill: Cover with plastic wrap and refrigerate for at least 4 hours, or ideally overnight, to let the flavors meld.

By following these steps, you can effortlessly create a stunning and delicious Black Forest Trifle perfect for Christmas!