Start by crushing the chocolate creme sandwich cookies in a food processor until you achieve a fine crumb, which should take about 30 seconds. Melt the unsalted butter and combine it with the cookie crumbs in a mixing bowl. Stir until the crumbs are evenly coated, then divide the mixture among small glasses, pressing down firmly to form a crust. Refrigerate for at least 15 minutes to set.

In the bowl of a stand mixer, combine the softened mascarpone cheese, chocolate hazelnut spread, powdered sugar, and vanilla extract. Beat on medium speed for about 2 minutes, until the mixture is smooth and creamy. Meanwhile, in a separate bowl, whisk the heavy cream until soft peaks form, which should take about 3-4 minutes. Gently fold the whipped cream into the mascarpone mixture in thirds, making sure to keep it light and airy.

Once your crust is set and the mascarpone cream is light and fluffy, it's time to assemble your Chocolate Hazelnut Mascarpone Cups. Using a spoon or piping bag, dollop or pipe the mascarpone cream over the prepared cookie crust in each glass. Make sure to fill them generously, leaving a little room at the top. Cover the cups with plastic wrap or lids and refrigerate for at least 2 hours, but overnight is best for optimal flavor and texture.

Prior to serving, take the cups out of the refrigerator and add your favorite garnishes. A dollop of whipped cream, chocolate flakes, or even toasted hazelnuts can elevate the presentation. Enjoy the creamy decadence of your Chocolate Hazelnut Mascarpone Cups chilled.