Instructions:
- Preheat oven to 350°F (175°C). Grease and line the bottoms of two 8-inch (20cm) cake pans with parchment paper circles.
- Whisk together the sifted flour, sugar, baking powder, and salt in a large bowl.
- In the mixer bowl, beat the softened butter until pale and creamy (about 3 minutes). Beat in the lemon zest until fragrant.
- Beat in the eggs one at a time, ensuring each is fully incorporated before adding the next. Scrape down the bowl well.
- Gently mix the flour mixture and the milk mixture into the butter mixture in three additions, starting and ending with the flour (Dry, Wet, Dry, Wet, Dry). Mix only until just combined—do not overmix.
- Stir in the lemon juice and vanilla extract by hand with a spatula.
- Divide batter evenly between the prepared pans. Bake for 28–32 minutes, or until a wooden skewer inserted into the centre comes out clean.
- Let the cakes cool in the pans for 10 minutes before inverting them onto a wire rack to cool completely.
- To make the frosting, beat the softened butter until fluffy. Gradually add the sifted powdered sugar, alternating with the lemon juice and zest. Beat until light and fluffy, adding cream/milk as needed to reach a spreadable consistency.
- Once layers are completely cool, level the tops if necessary. Place the first layer on a serving plate, spread with a generous layer of frosting, top with the second layer, and finish by frosting the top and sides of the cake.