Prepare the Custard Mixture: In a saucepan, combine the pumpkin puree, creamy coconut milk, and aromatic palm sugar. Heat the mixture gently over medium-low heat, stirring occasionally, until the palm sugar fully dissolves. This step infuses the coconut milk with the pumpkin's natural sweetness, creating a flavorful base for the custard. Once dissolved, remove the saucepan from heat and allow the mixture to cool slightly, enhancing its texture and flavors.

Whisk Eggs: While the pumpkin mixture cools, take a separate bowl and whisk the eggs thoroughly. Add a pinch of salt for balance and a hint of vanilla extract to enhance the custard's fragrance and complexity. Whisk until the eggs achieve a smooth consistency, ensuring they are well incorporated for a uniform texture.

Combine and Blend: Slowly pour the cooled pumpkin mixture into the bowl of whisked eggs, stirring continuously to prevent the eggs from curdling. This gradual incorporation blends the creamy pumpkin-infused coconut milk with the eggs, ensuring a smooth, velvety custard base that captures the essence of Thai dessert tradition.

Strain for Smoothness: For a silky texture, strain the custard mixture through a fine sieve into a heatproof dish or individual ramekins. This step removes any lumps or solid particles, ensuring the custard is impeccably smooth and pleasing to the palate.

Steam to Perfection: Place the dish(es) in a steamer over medium heat. Steam gently for approximately 30-40 minutes or until the custard is set with a slight jiggle in the center when gently shaken. This gentle cooking method allows the custard to set evenly without overcooking, preserving its delicate texture and flavors.

Cool and Serve: Once steamed, remove the custard from the heat and allow it to cool to room temperature. Serve Sang Kaya Fak Thong chilled or at room temperature, allowing its flavors to meld and develop. Top with a little toasted coconut or a drizzle of coconut cream for an extra treat.