No, you cannot make ricotta with only heavy cream.  Ricotta is made from whey and milk. You would need to add some type of milk product to create the ricotta cheese. Some alternatives to making ricotta cheese include using store-bought ricotta cheese or using a recipe that calls for cottage cheese or cream cheese.  These ingredients will give your ricotta cheese a similar texture and flavor.  However, if you are looking for a vegan alternative, you can use silken tofu in your recipe. This will give the ricotta cheese a softer texture. Whatever path you take, make sure to follow the recipe exactly to end up with delicious and authentic ricotta cheese. Enjoy!