Yield: one 8-inch cake
Ingredients:
Cake
2 cups all purpose flour
1 1/2 cups sugar
3/4 tsp baking powder
1 tsp baking soda
1/2 tsp salt
3 eggs
2/3 cup oil
2/3 cup lemon juice
3/4 cup sour cream
Lemon Curd
1/4 cup fresh lemon juice (about 1-2 lemons)
2 tsp finely grated lemon zest
1/3 cup sugar
4 egg yolks
3 tbsp butter (I used unsalted)
Lemon Buttercream
1 1/2 cups butter
1 1/2 cups shortening
12 cups (3 lbs) powdered sugar
3 tsp finely grated lemon zest
6 tbsp lemon juice
3/4 tsp vanilla
1-2 tsp water - plus more to the consistency you want
Instructions:
Cake
1. Combine flour, sugar, baking powder, baking soda and salt in a large bowl and whisk together.
2.Add eggs, oil and lemon juice. Beat until smooth.
3. Add sour cream and beat until smooth.
4. Bake at 350 degrees in two 8-inch pans for about 25 minutes or until done.
Lemon Curd
1. Combine all ingredients in a double boiler (or in a metal bowl over a pot of simmering water, like I did).
2. Heat while stirring constantly with a whisk.
3. It is done when it's thick enough to coat the back of a spoon. You will be able to tell it has thickened, but I wouldn't say that it's "thick."
4. Refrigerate until cool and thick.
Lemon Buttercream
1. Beat butter and shortening together until smooth.
2. Add 6 cups of powdered sugar, one at a time, beating to combine.
3. Add lemon juice, lemon zest and vanilla and combine.
4. Add the remaining powdered sugar and beat to combine.
5. Add water to get the consistency you want, starting with 1/2 tsp, beat to combine.
To assemble the cake:
1. Divide the cake into four layers by slicing each cake in half.
2. Fill two layers with lemon buttercream and the other two with lemon curd.
3. Frost the outside of the cake.