Prepare the bottom layer by mixing the soaked glutinous rice, thin coconut milk, and salt in an 8-inch square pan, then tuck the knotted pandan leaves directly into the rice.

Place the pan in a preheated steamer and steam over high heat for 25 minutes until the rice grains are tender and translucent, then remove the pandan leaves and discard them.

Use a spatula to press the hot steamed rice down firmly to create a compact, even layer with no gaps so the custard layer does not seep through.

Prepare the custard layer by whisking the eggs, sugar, thick coconut cream, pandan juice, all-purpose flour, and cornstarch in a bowl until completely smooth and free of lumps.

Strain the custard mixture through a fine-mesh sieve into a saucepan, then cook over low heat for 3 to 5 minutes, stirring constantly until it slightly thickens to a thin batter consistency.

Gently pour the warm, thickened custard mixture over the compacted glutinous rice layer, using the back of a spoon to smooth out any small bubbles on the surface.

Steam the entire cake over low-medium heat for 25 to 30 minutes with the steamer lid wrapped in a clean kitchen towel to prevent water droplets from falling onto the custard.

Let the Seri Muka cool completely at room temperature for at least 3 hours, then slice into diamonds using a lightly oiled knife for clean cuts before serving.