Rinse 1 cup of uncooked long-grain white rice. Put in a bowl with ½ cup of blanched slivered almonds and 1 Ceylon cinnamon stick, broken up. Measure 6 cups of water and add half. Cover and refrigerate for at least 8 hours.
Blend the soaked mixture with the remaining water for 2-5 minutes, until smooth, working in batches if needed.
Strain through a nut-milk bag or fine sieve. Repeat until no grittiness remains.
Stir in 3 cups of whole milk, 355ml of evaporated milk, ½ cup of granulated sugar, and 1 teaspoon of vanilla extract until dissolved. Chill, stir and serve over ice with a little ground cinnamon.
