Measure out all the ingredients and prepare the ramekins lined with lightly greased cupcake liners first.
Add the milk and oil into a small pot and warm over low heat until the sugar and salt dissolve. Remove the pot from heat.
Then separate the egg yolks from the egg whites. Place the egg whites in a clean measuring cup / small tall container and refrigerate.
Add the egg yolks to the warm milk mixture and mix until combined. Then sift the cake flour and baking powder into the milk mixture until just combined - do not overmix. Then sieve the batter for a smoother texture (or use your fingers to press out any lumps).
Fill the water tank of the Cubie Steam Convection Oven, then set the oven to steam-medium for 3 minutes to heat up the oven.
Meanwhile, take the egg white out from the fridge and whisk using an electric whisk until slightly frothy. Add in the cream of tartar. Then add the sugar a little at a time. Alternate adding more sugar and whisking the egg white.
Continue to whisk until the egg white reaches stiff peak consistency. Test the consistency by lifting up the whisk to see if the egg white tip forms a stiff peak.
Add about 2 tbsp of the meringue to the batter and fold in gently using a figure of eight motion. Be careful not to overmix or fold in too vigorously as the meringue will deflate and the cake will not rise well.
Once combined, add in the rest of the meringue into the batter and fold in gently until just combined.
Pour the batter into the ramekins. Place the ramekins over the steaming tray provide and cover loosely with a sheet of cling wrap. Steam immediately in the Cubie oven using the 'steam-medium' function for about 12 minutes. Use a clean skewer to poke through the centre of the cake to test if it is done - the skewer should come out clean.
Remove the steamed cakes from the oven. Drop each cake from a height once to minimise shrinkage. Serve warm or at room temperature!
GETTING THE EGG WHITE FOAM RIGHT
The egg white foam helps to give a more airy and fluffy texture to the cake, so it is critical to get this right.
Using fresh cold eggs will give you a more stable egg white foam with smaller and more uniform bubbles.
Adding some cream of tartar (about 1/4 tsp) to the egg whites also helps to stabilize the egg white foam. You can substitute cream of tartar with lemon or lime juice. But if you are very skilled at handling egg white foam, you can skip this step.
Make sure you whip the egg white until it reaches soft peak consistency.
Do not let the egg white foam stand for too long. Once it is whipped, the cakes should be in the oven within 10-15 minutes.
Be very gentle when mixing the egg white foam into the batter - you want to minimise deflating the bubbles in the foam. It is best to use a silicon spatula to cut a path and fold the foam into the batter using a figure of eight motion. Avoid using a wooden spoon and do not use an electric mixer for this step.
Adding 2 tbsp of the egg white foam to the batter first helps to lighten it, making it easier to mix in the rest of the egg white foam without deflating it.
OTHER COOKING TIPS / VARIATIONS
It is best to use cake flour, rather than all-purpose flour for this recipe, as cake flour gives a finer and light texture to the cake.
For chocolate steamed cake, add 1.5 tbsp of unsweetened cocoa powder to the cake flour before sifting.
For strawberry / mango / blueberry steamed cake, add 2 tbsp of finely chopped strawberries / mango / blueberries to the egg yolk mixture before adding the cake flour.
Expert Tip! Placing a clingwrap loosely over the ramekins minimises condensation on the surface of the cakes, allowing them to rise higher and more evenly. Give it a try and you will see a big difference in the cake texture!