Preheat your oven to 350°F (175°C). Grease and flour three 8-inch round cake pans.
In a large bowl, whisk together the flour, sugar, baking powder, and salt until well combined.
In another bowl, beat the softened butter until creamy. Gradually add the dry mixture, alternating with the milk, and mix until just combined.
Add in the eggs one at a time, mixing well after each addition. Stir in the lemon zest and lemon juice until the batter is smooth.
Divide the batter evenly among the three prepared cake pans. Bake for 25-30 minutes, or until a toothpick inserted in the center comes out clean. Allow cakes to cool in pans for 10 minutes, then turn them out onto a wire rack to cool completely.
In a saucepan, combine the raspberries, sugar, cornstarch, and lemon juice. Cook over medium heat, stirring gently, until the mixture starts to bubble and thicken. Remove from heat and let it cool slightly.
In a large mixing bowl, beat the softened butter until creamy. Gradually add powdered sugar, alternating with lemon juice, and mix until fluffy. If the frosting is too thick, add milk one tablespoon at a time until desired consistency is reached. Stir in the lemon zest.
Once the cakes are completely cooled, place the first layer on a serving plate. Spread a layer of raspberry filling, followed by a dollop of lemon buttercream. Add the second cake layer and repeat the process. Top with the final cake layer.
Use the remaining lemon buttercream to frost the top and sides of the cake. Feel free to make a rustic finish or a smooth finish as desired.
Garnish with fresh raspberries and lemon slices on top for a lovely visual appeal.
Notes
Serve on a beautiful cake stand and garnish each slice with raspberries and powdered sugar.