Method For Sponge:

1. Prepare two 6-inch tins by greasing them with oil and placing butter paper at the bottom. Preheat the oven to 180C (OTG mode: upper rod + lower rod + fan).
2. Sieve flour, baking powder, salt, and sugar in a bowl.
3. Add cold butter to the dry ingredients and rub it with your fingertips to get a crumbly texture.
4. Now, in a different bowl, mix eggs, oil, milk, and vanilla bean paste.
5. Add this liquid mixture to the crumbled mixture and form a smooth batter.
6. Pour the cake batter into the prepared tins equally.
7. Bake them at 180c (OTG mode: lower rod only) for 30-35 minutes or until the toothpick inserted in the middle comes out clean. 

Method For Buttercream:

1. In a saucepan, cook sugar and water until it reaches 115C
2. Meanwhile, in a bowl, beat egg yolks until they are very pale and fluffy.
3. Once the sugar water mixture reaches 115C, gradually add it to the fluffy egg yolk while still beating the egg yolk mixture simultaneously.
4. Beat until the mixture has completely cooled down.
5. Now add room temperature butter to it gradually.
6. The mixture will go from very voluminous to flat, but it will get voluminous again when you keep eating it.
7. Lastly add vanilla bean paste and beat again.

Method For Soaking Syrup:

1. Add vanilla extract to water and mix.

Assembly:

1. Demould the sponges and divide them into two parts with a cake leveller. ( we should have four layers of sponges)
2. Now, on a cake base, pipe a tiny amount of buttercream, then place a layer of sponge on it.
3. Soak the sponge with soaking syrup using a pastry brush, and pipe buttercream and smooth it out using a bent palette knife.
4. Place another layer of sponge, then repeat the same process as before.
5. Now pipe a thin layer of buttercream on top and side of the cake to crumb-coat it. Then smooth it out.
6. Keep it in the freezer for 15 minutes.
7. Now, pipe thick layers of buttercream all over the top and the sides of the cake to give it a final coating.
8. Remove the excess with a metal scrapper.
9. Now pipe spirals of buttercream on top using a 1M nozzle.
10. Lastly, decorate it by placing wild gipsy flowers randomly.