01 -
Preheat oven to 170°C (conventional setting). Line three 20 cm round baking pans with parchment paper and lightly grease the sides.
02 -
Sift together all-purpose flour, cornstarch, baking powder, baking soda, and salt in a medium bowl. Set aside.
03 -
In a large bowl, rub the granulated sugar and lemon zest together with your fingertips until the mixture resembles damp sand, releasing the citrus oils.
04 -
Add room temperature butter to the lemon-sugar mixture. Beat on high speed for 3 minutes until light and fluffy.
05 -
Add eggs two at a time, mixing between each addition on low speed until fully incorporated. Scrape down the sides as needed.
06 -
With mixer on low, add half of the sifted dry ingredients. Mix just until combined, then add sour cream, vegetable oil, lemon juice, and vanilla extract. Mix briefly, then add remaining dry ingredients until just combined.
07 -
Gently fold batter with a spatula to ensure even mixing. Divide evenly among the prepared pans.
08 -
Bake for 20–23 minutes, or until a cake tester inserted in the center comes out clean and layers remain pale without browning.
09 -
Allow cakes to cool in pans on a wire rack for 10 minutes. Carefully remove from pans and let cool completely on the rack.
10 -
Sift powdered sugar and freeze-dried strawberry powder together. In a stand mixer, beat butter for 4 minutes on medium-high speed, scrape the bowl, and beat for 2 minutes more.
11 -
Add the sifted powdered sugar mixture, vanilla extract, and milk in two additions to the whipped butter, mixing thoroughly and scraping down the bowl. Whip until light and creamy. Optionally, blend in a very small amount of red food colouring for a brighter hue. Mix on low speed for a final 2 minutes.
12 -
Place the first cake layer onto a serving plate or turntable. Spread a generous amount of strawberry buttercream over the layer using an offset spatula. Repeat with the second layer. Place the third layer on top and cover the cake with a thin crumb coat.
13 -
Refrigerate the cake for 20 minutes to set the crumb coat. Apply the remaining buttercream evenly over the cake, smoothing the sides and top, or creating a wavy design with the spatula if desired.
14 -
Garnish with fresh strawberries and lemon slices just before serving.