In a large bowl, combine the cooked rice, softened butter, honey, vanilla extract, salt, and cinnamon (if using). Mix well until all ingredients are thoroughly combined and the rice is coated.
Line a baking sheet with parchment paper. Using your hands or a measuring cup, form the rice mixture into small, round cakes, about 2 inches in diameter, and place them on the prepared baking sheet.
Chill the formed rice cakes in the refrigerator for at least 30 minutes to help them firm up.
Once chilled, remove the rice cakes from the refrigerator. If desired, sprinkle chopped nuts or seeds on top for added texture and flavor.
Serve the rice cakes as a sweet snack or dessert. Enjoy!