Preheat oven to 180°C (350°F).
In a large bowl, combine mashed sweet potato and avocado until smooth.
Add melted butter and flour, mixing by hand to form a dough.
Roll out dough on a floured surface or baking paper to ½ cm thickness. Cut out shapes with cookie cutters.
Place biscuits on a baking sheet lined with baking paper and bake for 10 minutes, checking frequently to avoid overcooking.
Let cool and serve.
Store in an airtight container for up to 3 days. Alternatively, freeze for up to 3 months. Thaw overnight in the refrigerator or at room temperature.
