01 -
Preheat oven to 175°C. Grease three 20-cm round cake pans, line with parchment paper circles, then grease and flour the parchment. Set aside.
02 -
In a small food processor, combine lemon zest with 3-4 tablespoons granulated sugar. Process until sugar is bright yellow and zest is finely flecked. Alternatively, rub zest and sugar together with fingers or muddle in a mortar and pestle.
03 -
In a bowl, whisk together whole milk, strained lemon juice, egg whites, and vanilla extract. Set aside.
04 -
In a stand mixer fitted with paddle attachment, mix flour, remaining granulated sugar, lemon-infused sugar, baking powder, and salt on low speed. With mixer running, add butter one piece at a time, blending until only pea-sized fragments remain.
05 -
Pour in half the egg white mixture; increase speed to medium-high and beat until light and fluffy, about 1 minute. Reduce speed; add remaining egg white mixture, blend until incorporated. Batter may appear slightly curdled.
06 -
Gently stir batter by hand, scraping bottom and sides to ensure complete mixing. Do not overmix. Evenly divide batter among prepared pans and smooth surfaces.
07 -
Bake for 18-22 minutes, rotating pans halfway, until tops are lightly browned and a toothpick inserted into center emerges clean.
08 -
Cool cakes in pans for 10 minutes, then remove and discard parchment. Allow cakes to cool completely on a wire rack before assembling.
09 -
Using an electric or stand mixer, beat butter and cream cheese until smooth, about 30 seconds. Add half the confectioners’ sugar and salt; blend on medium-low until incorporated. Scrape down bowl. Add remaining sugar, lemon juice, vanilla, and enough cream to reach desired consistency; mix until smooth. Finish by folding with a spatula.
10 -
Place one cake layer on a serving plate. Pipe a border of buttercream around the edge to form a wall. Fill center with 180-240 ml lemon curd. Repeat with second layer. Top with final layer, cover cake with remaining buttercream, smoothing or decorating as desired.