Preheat the oven to 180°C (356°F). Grease and line one 6-inch round cake pan.

Sift the all-purpose flour, cocoa powder, baking soda, and salt into a large mixing bowl.

Whisk the caster sugar into the sifted dry ingredients until evenly combined.

Add the milk, vegetable oil, vanilla extract, and water to the dry mixture.

Whisk the batter until smooth and no dry streaks remain.

Pour the chocolate batter into the prepared 6-inch round cake pan. Smooth the surface with a rubber spatula.

Bake the cake for 15 to 20 minutes at 180°C (356°F). Test the center with a skewer; it should come out clean.

Remove the cake from the pan and cool it completely on a cooling rack.

Melt the dark chocolate in a microwave-safe mixing bowl in short bursts, stirring between bursts.

Add the cream to the melted dark chocolate. Stir until the ganache is glossy and emulsified.

Crumble the cooled chocolate cake into a clean mixing bowl. Add the dark chocolate ganache.

Mix the crumbs and ganache until they form a soft, moldable chocolate dough.

Portion the chocolate dough into 6 equal pieces. Shape each piece into a small diya bowl with a raised rim.

Place a small strip of white chocolate ganache in the center of each diya to form the wick.

Pipe yellow-orange coloured whipped cream above each wick to create a flame shape. Arrange the finished edible diyas on a serving platter.