Pre-heat oven to 170°C and line a 8-inch springform cake tin.
Separate the eggs into yolks and whites.
Combine 2 tbsp oil, 1 tbsp water and 1/2 tsp vanilla essence. Set aside
Add 1/8 tsp salt and egg whites to the clean bowl of an electric mixer and beat on medium speed until frothy with big bubbles.
Add 1/2 tsp cream of tartar and beat on medium-high speed until foamy.
Gradually add in the sugar and then continue to mix on high speed until soft peaks.
Reduce the mixer to low speed and beat in the yolks, one at a time.
Keeping at low speed, add in the oil mixture and combine.
Add in the sifted flour (in 2 to 3 parts) and beat gently to combine.
Switch to a spatula and gently scrape down the sides of the bowl and fold in until just incorporated. Be careful not to over mix or you will deflate the batter.
Bake at 170°C for 30-35 minutes (mine took 30 minutes) or until a wooden skewer comes out clean.
Once the cake is completely cooled, level off the top and cut out a 6- inch round using a cake ring.
Slice the cake into two layers and cover with plastic wrap until ready to assemble to prevent it from drying out.