Step 1

Preheat the oven to 350°F. Prepare three 8-inch round baking pans, line the bottom with parchment paper, and grease the sides.

Step 2

In a large mixing bowl, combine the sugar, oil, eggs, and lemon extract. Beat on medium speed until the well is incorporated. Scrape down the bowl as needed

Step 3

Next, zest 2 lemons into the batter and then juice the lemons to get 1/4 cup of lemon juice. Add the lemon zest, lemon juice, and sour cream to the batter and beat until well combined.

Step 4

Combine the dry ingredients in a separate bowl, sift into the wet ingredients, adding half the dry ingredients at a time, with half of the buttermilk, and beat on low speed until combined. Add the remaining dry ingredients and buttermilk and continue mixing until combined. Use a spatula to scrape down the sides of the bowl and stir the batter to ensure it’s well-mixed.

Step 5

Divide the batter evenly between the three pans, about 1 2/3 cups of batter per pan. Bake at 350°F for 20-23 minutes. Test the cake for doneness by inserting a toothpick into the center of the cake. If the toothpick comes out clean, the cake is done. Remove from the oven and allow to cool completely.

Step 6

Cut the butter into 1-inch blocks. Beat the butter for 3-5 minutes until it is light and fluffy and reaches a spreadable consistency, scrape down the bowl frequently. Then add the cream cheese and cream together for 2-3 minutes until it’s fluffy and free of lumps.

Step 7

Next add the powdered sugar, lemon extract, and heavy cream. Beat on low speed until the powdered sugar has combined. Add the lemon curd, beat to combine then increase speed to medium-high and beat for a couple of minutes until smooth and creamy.

Step 8

Level the cake layers if needed. Place a dollop of frosting on your cake board and place the bottom layer of cake on top of that. Place half of the frosting in a large piping bag, then cut off the end of the piping bag.  Pipe a thick border (a dam) along the outside edge of the cake, once or twice.

Step 9

Spread half of the lemon curd in the middle of the cake. Add the second layer of cake, inverted and repeat the above steps using all of the remaining lemon curd. Next, add the final layer of cake on top, inverted.

Step 10

Use the piping bag to fill in any gaps between the layers and to create a crumb coat. Using an offset spatula or icing smoother, wipe away the excess frosting, leaving you just enough to coat the outside of the cake.

Step 11

With the remaining frosting, proceed to frost the top and sides of the cake using an offset spatula. Garnish with lemon slices.