1-Preheat and Prepare First, preheat your oven to 180°C (350°F) or 160°C (320°F) fan for 20 minutes, and grease and line three 20cm (8-inch) cake pans to prevent sticking.

2-Mix the Dry Ingredients Next, whisk together 2 cups of plain or all-purpose flour, 2 1/2 teaspoons baking powder, and 1/4 teaspoon salt in a bowl to ensure they blend evenly.

3-Beat the Eggs and Sugar Then, beat 4 large eggs on medium speed for 30 seconds. Gradually add 1 1/2 cups of caster sugar over 45 seconds, and continue beating for 7 minutes until the mixture triples in volume and turns white, creating a light base for your cake.

4-Prepare the Wet Mixture Melt 115g (1/2 cup) unsalted butter with 1 cup full-fat milk without boiling, and keep it warm. In a separate bowl, mix this with 3 teaspoons vanilla extract, 3 teaspoons vegetable or canola oil, 1/3 cup lemon juice, 3 tablespoons lemon zest, and 1/4 teaspoon natural lemon extract if using. Lighten the hot mixture by whisking in some of the egg batter.

5-Combine and Bake Add the dry ingredients to the egg mixture in three additions, mixing gently just until combined each time. Slowly incorporate the milk mixture into the egg batter while mixing on low speed, scrape the bowl, and mix for 10 seconds until smooth and pourable. Divide the batter evenly into the pans, smooth the tops, and tap the pans three times to remove air bubbles. Bake for 23 minutes or until golden and a toothpick comes out clean, adjusting for oven placement as needed. Cool the cakes in the pans for 15 minutes, then turn out onto racks to cool completely upside down.

6-Make the Frosting For the frosting, combine 1 1/3 cups caster sugar and 6 1/2 tablespoons plain flour in a saucepan and toast lightly for 30 seconds. Slowly whisk in 1 1/3 cups full-fat milk and cook over medium heat, stirring constantly until thick like custard. Remove from heat, cover with cling wrap pressed against the surface, and cool fully (20 minutes at room temperature, then 30 minutes in the fridge). Beat 300g softened unsalted butter until creamy, add the cooled roux gradually while mixing, then mix in 3 teaspoons lemon zest, 4 tablespoons fresh lemon juice, and a pinch of salt. Beat for 2-3 minutes until light and fluffy.

7-Assemble the Cake Place one cake layer upside down, spread frosting 3-4mm thick, repeat with layers, and cover the top and sides. Decorate with lemon slices or edible flowers for a nice touch.