Make the inner layer by combining all of the ingredients and mixing until smooth.
Next make the outer layer. Mix all ingredients except the cooked jasmine rice, coconut flakes, and 2 tablespoons of the club soda. Pound or blend the rice and coconut flakes with the 2 tablespoons of club soda until they form a fine paste and then incorporate into the rest of the ingredients you just mixed.
Heat your seasoned khanom krok pan over medium heat. If you're not able to find a khanom krok pan, an Ebelskiver pan apparently works just as well.
Add a drop of canola oil (~⅛ teaspoon) to each well and let it get hot. It should be hot enough that when you add the batter it sizzles.
Add 1 tablespoon of the outer layer to each well and then lift the pan (using a pan holder - it's hot!) and swirl it until the batter forms a thin layer around the entire well.
Add 1 tablespoon of the inner layer to each well to fill it. If you want to add toppings, add them at this point. Then, cover the pan with a top and let it steam for about 5-6 minutes until the bottom layer is golden brown and the top layer is fairly solid.
Using a butter knife, gently lift each custard from the pan. Serve the khanom krok in pairs of two.