Line a bread pan lengthwise and crosswise with plastic wrap leaving enough overhang to be used as a cover for the dessert as it sits in the fridge.
Using the whisk attachment, pour 3 cups of heavy cream into the bowl of your stand mixer or large bowl of choice if using a hand mixer.
Next, add Powdered Sugar and Vanilla to the Heavy Cream.
Whip until stiff peaks form.
Spread some of the whip cream along the sides and bottom of the prepared pan.
Spread some of the whipped cream onto each piece of Brownie Brittle and layer into the pan. You should get 4-5 rows of Brownie Brittle.
Once you’ve filled the pan, put a layer of whip cream over the top.
Layer the remaining Brownie Brittle pieces over the top and cover with more whip cream.
Cover the whipped cream with the excess plastic wrap lining the pan.
Refrigerate for 6-8 hours.
Next, unmold from the pan and invert onto a plate or stand.
Slice and serve using the smallest crumbs from Brownie Brittle as topping.