Preheat oven to 325°F and line a muffin tin with cupcake liners.Mix crushed chocolate cookies and melted butter, then press into each liner.Beat cream cheese and sugar until smooth.Add eggs, one at a time, mixing gently.Stir in melted chocolate and vanilla.Fill liners three-quarters full with cheesecake batter.Bake 16–18 minutes or until set.Cool at room temperature, then chill for 2 hours.Pipe whipped cream onto each cheesecake.Place a strawberry half on top to create a gnome hat.Add a whipped cream dot and mini chocolate chip eyes.Dust with powdered sugar and serve.