Creating this No Bake Summer Berry Icebox Cake is incredibly simple. Just follow these easy steps:

1. Whip the Cream: In a large mixing bowl, beat the heavy whipping cream until soft peaks form. Gradually add the powdered sugar and vanilla extract, continuing to beat until stiff peaks form.
2. Layer the Ingredients: In a 9×13-inch pan, spread a thin layer of the whipped cream mixture on the bottom.
3. Add Graham Crackers: Arrange a layer of graham crackers over the whipped cream, breaking them as needed to cover the entire surface.
4. Spread More Whipped Cream: Smooth another layer of the whipped cream mixture over the graham crackers.
5. Add Berries: Sprinkle half of the mixed fresh berries over the whipped cream.
6. Repeat Layers: Repeat the layering process with another set of graham crackers, followed by whipped cream, and then the remaining berries.
7. Finish with Cream: Top with a final layer of the whipped cream mixture, spreading it evenly.
8. Chill: Cover the cake with plastic wrap and place it in the refrigerator. Chill for at least 4 hours, or overnight for optimal flavor and texture.
9. Serve: Once set, slice the cake into squares, and garnish with fresh mint leaves if desired.

By following these simple steps, you can have an impressive summer dessert ready in no time.