In a clean bowl, separate the eggs. Keep the egg white bowl cool in the fridge.

In a clean bowl, mix well vegetable oil and milk. Sift in cake flour and cocoa powder and mix well. Mix in egg yolks and set aside.

Preheat the oven to 150℃(302℉). Line the baking tray (28*28*2.6cm) with parchment paper or baking mat.

Take the egg white out of the fridge. Add in lemon juice, vanilla extract and sugar; use a hand mixer to beat until soft peaks form. Take a scoop of whipped egg white and gently fold it in to the batter until just combined. Pour all the batter into the whipped egg white and gently fold it in until just combined.

Pour all the batter into the baking tray. Smooth it out and give it a tap or two. Send into the oven to bake for 32 minutes. Take the cake out of the oven and let the cake cool down on the cooling rack before take it out of the cake pan. When the cake is cool to touch, release the sides of the cake with an icing spatula, turn the whole cake pan upside down on the parchment paper. Take off the pan, and peel off the baking mat.

Cover: In a clean bowl, bring together chocolate chips and hot milk. Mix to melt the chocolate chips. Cover with plastic wrap and let set in the fridge for 30 minutes.

Topping and Filling: In a clean bowl, bring together heavy cream and sugar. Use a hand mixer to beat until thickened, transfer a scoop or two into a piping bag. Keep it cool in the fridge. Keep beating rest of the heavy cream until stiff peaks form.

Spread the whipped cream on to one side of the cake. Smooth it out and roll the cake up in to a cake roll. Cover the cake with chocolate and let set in the fridge to chill until set. Slice the cake into 4 pieces, top with thickened heavy cream. Garnish with strawberry, blueberry, and raspberry and some coconut flakes.