Simmer the base: In a medium saucepan combine heavy cream, coconut milk, cinnamon stick, sweetener, and salt. Bring to a gentle simmer over medium-low, stirring until sweetener dissolves.
Add riced cauliflower: Stir in cauliflower; keep mixture at a lazy bubble. Cook 8–10 min, stirring occasionally, until cauliflower is tender and liquid thickens.
Finish with vanilla: Remove cinnamon stick. Stir in vanilla and taste — add more sweetener if desired.
Serve: Ladle into four small bowls. Dust with ground cinnamon or sprinkle toasted coconut. Enjoy warm, or chill 2 hours for classic cold pudding.