Lemon Raspberry Cake

My best friend and I have an agreement that we will make each other's birthday cakes every year.  There is usually a planning period where we map out exactly what kind of cake we will make (it's a collective process) and this year this was her request.  Dense lemon cake, fruity raspberry curd, and light lemon buttercream over it all.  Her birthday is today, so I made her cake yesterday and we had the first tastes last night.  Yummy.  It might be a little fancy for everyday, but for a birthday or other special occasion, it is awfully good.

Makes 9-inch layer cake

3 tablespoons fresh lemon juice (about 3 lemons)
3 tablespoons lemon zest (about 3 lemons)
1 cup sour cream
1 1/2 cup flour, plus 2 tablespoons for pans
1 3/4 cup cake flour
1 tablespoon baking powder
1/2 teaspoon salt
1 cup butter, plus 1 tablespoon for pans
1 3/4 cups sugar
4 eggs
Raspberry Curd
Lemon Buttercream Frosting

1. Grease layer cake pans with tablespoon butter.  I also like to cover the bottom of my layer pan with a round of parchment, cut to fit, and grease that as well.  Place the 2 tablespoons flour in one cake pan, shaking to coat pan, and then shake excess into other pan and coat it in flour.  Discard excess flour once both pans are coated.
2. In small bowl, mix together lemon juice and zest and sour cream.  Set aside.
3. In medium bowl, combine flours.  Using a small whisk, mix baking powder and salt into flours.  Set aside.
4. In bowl of an electric mixer, beat butter and sugar together until fluffy.  Scrap sides of bowl.  Add eggs, one at a time, and beat until mixture is fluffy and incorporated.
5.  Beat roughly 1/4 of the flour mixture into the butter mixture.  Add 1/3 of the sour cream mixture and beat well.
6. Repeat step 5 until all of the flour mixture and sour cream mixture is incorporated into butter mixture.  You should end with flour.  When adding these ingredients, be sure to beat as little as possible to prevent cake from being tough.
7. Divide batter evenly between prepared pans.  Bake layers in 350 degree oven for 30-40 minutes or until a toothpick inserted in the center of each layer comes out clean.  Place cake pans on oven rack to cool completely.
8. Remove cakes from pans.  If parchment was used, peel parchment off layer bottoms.  Using thread pulled taut or a serrated knife, split each layer in half horizontally.  This should leave you with four layers of cake.
9. On plate or serving platter, arrange one layer of cake.  Spread 1/2 cup raspberry curd over cake layer, making even and spreading within 1/4 inch of cake edge.  Top with a second layer of cake.  Spread second layer with 1/2 cup curd like the first, then top with a third cake layer.  Spread remaining curd over third cake layer.  Top with fourth and final layer.
10.  Spread a very thin layer of frosting over entire cake.  This should seal in crumbs and make cake more stable (it can shift somewhat with four layers). Refrigerate cake for 20-30 minutes or until frosting is hard.
11. Frost cake with remaining frosting, evenly distributing buttercream over the cake.  Allow cake to sit for at least 2 hours before serving to allow frosting to firm up and cake to settle.  Cake can be refrigerated in a covered container for up to three days.