For the Cake
6 tablespoon butter
6 tablespoons vegetable oil
1⅓ cup sugar (divided, 1 cup in butter, ⅓ cup in egg whites)
2 teaspoons vanilla or raspberry extract
2 teaspoons grated lemon zest
3 cups cake flour
1 tablespoon baking powder
½ teaspoon salt
1 cup whole milk
6 egg whites
For the Simple Syrup
½ cup lemon juice
½ cup water
¾ cup sugar
For the Cake
Preheat the oven to 350℉ and prepare 3 9-inch round cake pans with butter and flour.
Cream the butter, oil and 1 cup of sugar in a stand up mixer with the paddle attachment. Beat for 3 minutes until it's light and fluffy. Add in the extract and zest. If you want the cake to have a mild flavor, use the vanilla; if you want a hint of raspberry in the cake, use that.
Sift the flour, baking powder and salt in a large bowl. With the mixer on low, add a third of the flour then half of the milk. Repeat the process ending with a third of the flour. Beat until the flour is just incorporated. Transfer the batter to a large bowl.
Wash and dry the mixing bowl. Remove all oil from the bowl and wipe it clean.
With the whisk attachment, beat the egg whites on medium speed until they form soft peaks. Gradually add in the ⅓ cup sugar and whip until stiff peaks form.
Fold the half of the egg whites into the cake batter with a large rubber spatula. Then fold in the other half until combined. You do not want to mix the two and burst the air bubbles in the egg whites.
Wet your Bake Even Strips, wring them out, and wrap them around your prepared pans.
Divide the batter between the three pans and bake for 25 to 30 minutes. The sides should start to pull away from the pan and the top should be set.
Let cool in the pans for at least 30 minutes, then remove and allow to completely cool on a wire rack.
Wrap in plastic and place in the fridge overnight or in the freezer for up to a week.
For the Simple Syrup
Combine the ingredients in a small saucepan and bring to a boil, stirring until the sugar is dissolved. Remove from the heat and and cool to room temperature. Store in a closed container for up to a week. Only add to the cake when you are ready to frost it.
1 cup fresh lemon juice
¼ cup butter
2 tablespoon heavy cream
2 egg yolks
1 cup sugar
½ teaspoon salt
½ teaspoon vanilla
Use an enamel, glass, or stainless steel saucepan and combine the lemon juice, butter, and cream. Cook over medium heat just until it scalds, but not boiling.
In a large glass bowl, whisk the eggs, egg yolks and sugar together. Then slowly add ¼ of the hot lemon mixture to the eggs and temper the eggs. Whisk constantly while adding the hot mixture to the eggs making sure that you don't cook the eggs. Continue to add the hot lemon to the egg until it's completely whisked in.
Pour it back into the sauce pan and cook over medium heat. Stir it constantly with a wooden spoon. Scrape along the bottom and sides of the pan watching for the mixture to thicken. To test for proper thickness, remove the spoon and drag your finger across the back of it. You should leave a defined trail behind that does not immediately fill back in.
Strain the mixture through a fine mesh into a clean bowl. Stir in the salt and vanilla.
Seal the bowl or pour it into a mason jar and refrigerate.
Your lemon curd should be good for 5 days.
While the syrup is cooking, whip your eggs and egg yolks until they are pale and light.
When the syrup is ready, turn the mixer to low and very, very slowly add the syrup to the eggs. Allow it to drip down the sides of the bowl into the eggs.
Increase the speed to medium and whip the mixture until the bowl is cool to the touch. This may take 5 minutes. Do not rush it.
Reduce the speed of the mixer back to low and slowly add in the butter one Tablespoon at a time. Once all the butter has been added, increase the speed to medium and whip for another 5 minutes. It'll get pretty ugly before it gets beautiful.
Finally add the salt and get the rest of the cake ready to be frosted.
Assemble the Cake
Divide the buttercream into two 3 cup bowls. Cover one bowl set to the side; add ½ cup of the lemon curd to the second one. Mix the lemon curd and frosting together. Add ½ cup of the lemon buttercream into a pastry bag.
Place one of the cakes on a cake round or directly on to a cake platter. Brush on, or use a squirt bottle, about ⅓ cup of the lemon simple syrup. Be generous.
Spoon 1 cup of the lemon buttercream on to the cake and smooth out. Add a frosting dam around the cake then fill in with ½ cup of lemon curd.
Add in a few raspberries. Top with second cake.
Repeat with the syrup, frosting, dam, curd and more raspberries. Top with the third cake upside down so that the edges are squared off. Add the simple syrup to the cake then add a thin crumb coating with any lemon buttercream remaining. Place into the fridge to firm up for 1 hour.
Once it has firmed up, frost the cake with the reserved plain frosting. You may have to beat it a wooden spoon to smooth it out again if it separates. Frost and decorate as desired. I kept it basic and simple.
Top the cake with ⅓ cup of lemon curd and a few pretty raspberries.
Store in an airtight container in the fridge for up to 2 days (if it lasts that long).