Creating a Black Forest Trifle is straightforward if you follow these simple steps:

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

2. Whip the Cream: In a large bowl, beat the heavy cream with an electric mixer until soft peaks form. Gradually add the powdered sugar and vanilla extract. Continue beating until stiff peaks form.

3. Cut the Cake: Slice the cooled chocolate cake into small cubes.

4. Layer the Ingredients: In a large trifle dish or individual serving cups, start layering by placing a third of the cake cubes at the bottom.

5. Add the Cherries: Spoon a third of the cherry pie filling over the cake layer, ensuring even coverage.

6. Include the Cream: Add a generous layer of the whipped cream on top of the cherries.

7. Repeat Layers: Continue this sequence: cake, cherries, and cream, until your dish is full, finishing with a layer of whipped cream on top.

8. Chill: Cover the trifle with plastic wrap and refrigerate for at least 2-4 hours or overnight for best flavor.

9. Garnish: Just before serving, garnish the top with chocolate shavings or curls for a festive touch.