Once the brownies have cooled, add a layer (using your fingers) in the bottom of a trifle dish.
In a large mixing bowl add the 2 cups of heavy cream and beat using a hand mixer, until stiff peaks form.
2 Cups Heavy Whipping Cream
Add ¾ Cup Nutella to the cream and beat again until well mixed. Set aside.
1 (13 Ounce) Jar Nutella
Using a spoon drizzle spoons of the remaining Nutella over the first layer of brownies on the bottom of the trifle dish.
1 (13 Ounce) Jar Nutella
Spoon half of the chocolate pudding on top.
Add a layer of hazelnut wafer cookies (reserving some to crumble on top).
1 (5 Ounce) Pack Hazelnut Wafer Cookies
Spoon half of the nutella cream over the top of the cookies.
Add another layer of brownies on top.
Spoon the remaining chocolate pudding on top of the brownies again.
Top with the remaining nutella cream and sprinkle crushed hazelnut cookies on top for decoration.
Allow to sit in the refrigerator to "set up" for a few hours before serving.
Notes
There's no right or wrong way to put a trifle together, it's very forgiving. You may have some ingredients left over (like brownies, I had about a good 6 brownies left).