1. Preheat the oven to 350°F and line a 9×9-inch baking pan with parchment paper.

2. In a mixing bowl, stir together the brownie mix, 2 eggs, vegetable oil, and water until smooth.

3. Spread the batter evenly into the prepared pan.

4. Bake for 28 to 32 minutes, or until a toothpick inserted near the center comes out with a few moist crumbs.

5. Let the brownies cool completely in the pan.

6. In a large bowl, beat the softened butter until creamy.

7. Add the granulated sugar, cocoa powder, and vanilla extract, then beat until light and combined.

8. Add the remaining 2 eggs one at a time, beating well after each addition until the filling becomes smooth and silky.

9. Spread the chocolate silk layer evenly over the cooled brownies.

10. Refrigerate for 1 to 2 hours until the layer is set.

11. In a chilled bowl, whip the heavy whipping cream with powdered sugar until soft to medium peaks form.

12. Spread or pipe the whipped cream over the chocolate layer.

13. Sprinkle chocolate shavings on top.

14. Chill for 30 more minutes before slicing and serving.