Heat oil in a large pan over medium heat until shimmering, about 3 minutes. Carefully add the cannelloni pasta in batches, frying for 2-3 minutes or until they turn a beautiful golden brown. Use a slotted spoon to transfer the fried cannelloni to a cooling rack lined with paper towels to drain excess oil.

In a small bowl, dissolve the instant coffee in warm water, stirring until fully combined. Briefly dip each fried cannelloni into the coffee mixture for 1-2 seconds, ensuring they soak up the flavor without becoming soggy.

In a large mixing bowl, whip the heavy cream with powdered sugar using an electric mixer on medium speed until stiff peaks form, about 3-5 minutes. Gently fold in the mascarpone cheese until smooth.

Fill a piping bag with the mascarpone mixture and pipe it into each coffee-dipped cannelloni. Arrange the stuffed cannelloni on a platter, then refrigerate for at least 4 hours.

Once chilled, dust the tops lightly with sifted powdered sugar or cocoa powder before serving.