In a large saucepan over medium heat, melt the butter.
2. Step
Add the marshmallows and stir until melted. Add the crispy rice cereal and stir to coat.
3. Step
While the crispy rice cereal mix is still warm, transfer them to a greased 10-inch (25 cm) springform pan.
4. Step
Using a greased measuring cup, press down into the cereal to form to the pan. Press the edges against the springform pan to create walls. Set aside.
5. Step
Place the chocolate in a small microwave-safe bowl and pour the heavy cream on top. Microwave in 30-second intervals, stirring until melted, about 1 minute.
6. Step
In a large bowl, mix the cream cheese, sugar, and vanilla until smooth.
7. Step
Pour in the melted chocolate and stir to incorporate.
8. Step
Add 1½ cups (90 g) of whipped cream to the chocolate mixture and fold with a spatula until combined.
9. Step
Pour the cheesecake mixture into the crispy rice base and smooth the top with a spatula.
10. Step
Refrigerate for 3-4 hours or overnight, until the cheesecake is set. Release the springform.
11. Step
Put the remaining cup of whipped cream in a piping bag fitted with a star tip and decorate the top of the cheesecake.
12. Step
Use a vegetable peeler to shave the chocolate into the middle of the cheesecake.
