Preheat the oven to 160°C fan-forced (180°C conventional). Prepare your two 20 cm (8-inch) round pans by greasing them well and lining with parchment paper.

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

Whisk together the canola oil, melted butter, caster sugar, eggs, white vinegar, buttermilk, vanilla extract, and red food coloring in another bowl.

Combine the wet and dry ingredients gently, stirring until just smooth. Avoid overmixing.

Divide the batter evenly between your prepared pans. Bake for 35–40 minutes, or until a skewer inserted comes out clean.

Cool the cakes in their pans for about 10 minutes, then move them to a wire rack to cool completely.

Prepare the frosting by beating the room temperature unsalted butter and cream cheese together until fluffy. Gradually add the powdered sugar, lemon juice, and vanilla extract, mixing until pale and creamy.

Level the tops of the cooled cakes if they have domed. Spread frosting generously between the layers and envelop the entire cake.

Chill the frosted cake in the refrigerator for 1–2 hours before serving.

Optional: Add a sprinkle of cocoa powder or chocolate shavings on top for an extra touch of elegance!