Preheat the oven at 160°C.

In a mixing bowl, add oil, milk and all-purpose flour. Whisk until well combined.

Add egg yolks, one by one, and stirring after each addition.

Now divide this batter into two equal parts.

Batter 1: Add vanilla powder or liquid essence and mix.

Batter 2: Add cocoa powder and mix.

Keep two parts for later use.

Now it’s time to make the meringue. In a separate bowl, add egg whites, salt, lemon juice and whisk until soft peaks are formed.

Add powdered sugar at this stage and whisk again until stiff peaks are formed.

Now add half meringue into the batter 1 and remaining half into the batter 2.

Gently fold in meringue using a spatula. So not whisk at this stage otherwise the meringue will deflate.

Take an 8-inch pan and prepare the sides using the wax paper.

Add the batter 2 into the pan and level it using a spatula.

Gently pour dallops of batter 1 on top and level out with the spatula.

Now using a lollipop stick or the back of a spoon, make wave pattern on the inner side of the tin (please watch the video for the demonstration).

Put some chocolate chips on top.

Fill a tray with water and place the baking pan on it. Water level should be 1 cm.

Place it in the middle section of the oven. Bake at 160°C for 60 to 65 minutes using only lower heat.

It is ready when the tooth pick inserted comes out clean.

Enjoy with tea or coffee.