- 7 ounces tea biscuits, broken into small pieces
- 1/2 cup butter, melted
- 1 egg
- 1/3 cup dark cocoa powder
- 1/4 cup white sugar
- 1 tablespoon chocolate-hazelnut spread (such as Nutella®)
- Mix tea biscuits, butter, egg, cocoa powder, and white sugar together in a bowl to form a moist but stiff dough. Stir in chocolate-hazelnut spread.
- Transfer dough to a large piece of parchment paper. Shape into a log with your hands. Wrap parchment paper around the log, twisting ends shut.
- Chill until firm, 2 hours in the freezer or 5 hours in the refrigerator. Cut into slices with a sharp knife.