Take your banana leaves and hold them briefly over low heat until they become soft and bendable. Wipe them clean, then use them to line your pan. Brush the leaves with coconut oil.
Mix your glutinous rice flour with 400ml coconut milk in a large bowl. Stir until smooth with no lumps. Set aside.
Pour the remaining coconut milk into a heavy pan over medium heat (175°C). Add your grated purple yam and stir continuously for 5 minutes until fragrant.
Pour your rice flour mixture into the pan, stirring as you go. Add sugar and salt. Keep stirring constantly for about 30-40 minutes. The mixture will get thicker and harder to stir – this is exactly what you want.
You'll know it's ready when the mixture pulls away from the sides of the pan and feels very thick when you stir. The temperature should be around 180°C. If you drop a small amount in cold water, it should form a firm ball.
Pour the mixture into your banana leaf-lined pan. Use an oiled spatula to smooth the top. While it's still warm, sprinkle generously with latik (toasted coconut curds).
Let it cool completely at room temperature for 2-3 hours. During this time, it will set and develop its chewy texture.
Once cooled, cut into diamond shapes using a sharp knife. Clean the knife between cuts for neat edges.
Serve your kalamay on fresh banana leaves. It pairs perfectly with hot ginger tea and makes a wonderful afternoon snack.
Remember: Good kalamay takes patience. The long, slow stirring is what gives it that perfect sticky, chewy texture that makes it so special.