Method for sponge

1. Preheat the oven to 180C (otg mode: upper rod, +lower rod + fan). Grease and line three 6-inch round tins with oil and butter paper. 
2. Now sieve all the dry ingredients in a bowl.
3. Mix all wet ingredients hot water, oil, and vinegar. 
4. Now carefully mix wet and dry ingredients to form a smooth batter. 
5. Pour the batter into the prepared tins equally and bake it at 180C for 30-35 min minutes (otg mode: lower rod only) 

Method for blueberry jam

1. Take a pan and cook blueberries and sugar together on medium flame. 
2. Smash blueberries with the help of the spatula.
3. When the mixture gets thicker, add salt and cream of tartar into this. 
4. Cook it for a few minutes and check the consistency with the help of a spoon. 

Method for ganache

1. Melt chocolate in the microwave and warm the cream. 
2. Mix the two until a smooth ganache is formed. 

Method for soaking syrup

1. In a bowl, mix water and vanilla essence. 

Assembly 

1. Demould the sponges and cut the dome if required. 
2. Place a cake board on the turn table and place some ganache in the center. Now, put the first layer of the sponge and soak it with soaking syrup using a pastry brush. 
3. Now pipe some ganache on the sponge and spread evenly. Pipe a layer of ganache on the edge of the cake(like a border) to fill the blueberry jam inside. Finally, add a layer of Blueberry jam. 
4. Place the second sponge layer and repeat the same process as above. 
5. Crumb-coat the cake with ganache and let it rest in the fridge for 20 -25 minutes. 
6. Now, frost the cake with a final layer of ganache and give a spiral look on the top. Take some ganache on a bent palette knife for the sides and give a stroke design. 
7. Lastly, decorate it with fresh blueberries, strawberries, red currants, and edible flowers.