1-First, preheat your oven to 160 °C (320 °F) with fan on, or 175 °C (350 °F) if no fan. Grease two 8-inch cake pans and line the bottom to prevent sticking. This step ensures your cake releases easily and keeps its shape.

2-Preparing the Cake Batter: Sift together the 2¼ cups (270 g) all-purpose flour, ¼ cup (25 g) cornstarch, 2 teaspoons baking powder, ½ teaspoon baking soda, and ½ teaspoon salt. Set aside for even mixing. In a large bowl, whisk together 1¼ cups (250 g) white granulated sugar, 3 large eggs at room temperature, ¾ cup (160 g) unflavored vegetable oil, 2½ cups (566 g) canned crushed pineapple in pineapple juice (not syrup), 1 teaspoon vanilla essence or extract, and 1½ tablespoons (20 g) fresh lemon juice until smooth and lump-free.

3-Gently fold the dry ingredients into the wet ingredients using a spatula until just combined, without overmixing. Divide the batter evenly between the prepared pans and tap the pans lightly to remove air bubbles. Bake for 30-33 minutes or until a toothpick inserted in the center comes out clean, then cool in the pans for 20 minutes before transferring to wire racks.

4-Making the Filling and Frosting: For the filling, combine ¾ cup (170 g) canned crushed pineapple, ¼ cup (50 g) white granulated sugar, ¼ cup (25 g) cornstarch, ¾ cup (175 g) full-fat milk, and 1 tablespoon (15 g) fresh lemon juice in a saucepan. Heat over medium, stirring continuously until thickened, then stir in ¼ cup (56 g) unsalted butter and optional yellow gel food color.

5-For the frosting, whip 1 cup (225 g) cold mascarpone, ½ cup (55 g) icing sugar, and 1 teaspoon vanilla on low speed, then add 1½ cups (335 g) cold whipping cream and whip to stiff peaks. Fold in ½ cup (112 g) drained crushed pineapple. Finally, assemble by layering the cake with frosting and filling as described.