Preheat the oven to 350°F. Prepare three 8-inch round baking pans, line the bottom with parchment paper and grease the sides. Prepare your bake even stripes if desired.
In a large mixing bowl, combine the sugar, vegetable oil, eggs, and lemon extract.
Beat on medium speed until the eggs and oil are well incorporated and the batter is lighter in color, about 2 minutes. Scrape down the bowl as needed.
Next, zest 2 lemons and (then set them aside to be juiced) add it to the batter as well as the sour cream. Beat until well combined.
Combine the dry ingredients in a separate bowl. Add half the dry ingredients followed by the lemon juice and half the buttermilk and mix just until the flour starts to incorporate.
Finally add the remaining dry ingredients and buttermilk and beat until all the ingredients are well combined.
Use a spatula to scrape down the sides of the bowl and stir the batter from the bottom to the top to ensure it’s well mixed.
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. Rotate your pans in the oven halfway through baking.
Test the cake for doneness by inserting a toothpick into the center of the cake. If the toothpick comes out clean, you cake is done.
Remove from the oven and allow to cool completely.
Toast the coconut on a sheet pan for 8-10 minutes, stir occasionally and watch closely to prevent it from burning.
Cook until coconut is light brown in color. Set the toasted coconut aside. Baking times will vary by oven, type of coconut and pans used.
For the Frosting:
Wipe down the inside of your stainless-steel bowl with vinegar to remove any grease. Combine sugar and egg whites in the bowl with candy thermometer attached.
Set the bowl over top of a pot with 1 1/4 cups water covering the bottom. Place over medium heat.
Stir constantly with a whisk until the mixture reaches 140°-160°F The sugar should be dissolved in the egg whites. You can test this by placing a drop on your finger tips and rubbing them together. The mixture should be completely smooth.
Immediately place the mixing bowl on your stand. Using the wire whisk attachment, beat the eggs white on low for 2 minutes than increase to medium high.
Beat for another 5 minutes. At this point, your frosting should have turned white and the body of the meringue starts to form.
Increase the mixing speed to high. It will start to look glossy as the peaks begin to form.
Beat for another 3-5 minutes until the bottom of your bowl is cool to the touch and your meringue has stiff peaks.
Turn your mixer down to medium-low. Slowly add your butter, 1 tablespoon at a time. As you add more butter, the frosting might appear to have curdled and lost its body, that’s ok. Scrape down the sides of the bowl.
Switch to the paddle attachment, add the coconut extract and continue beating on medium-high speed until your frosting start to have stiff peaks.
Beat for about 3-5 minutes.
Reserve a small handful of toasted coconut to garnish the cake. Use a food processor to grind approximately 2 cups of the toasted coconut into crumbs.
Pour the crumbs in your frosting and mix until combined.
To Assemble the Cake:
Use a cake leveler to cut the domes off the top of the cake. 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 fitted with a large open round tip, or simply cut off the end of the piping bag.
Pipe a thick dam around the outside edge of the cake, then spread half of the lemon curd in the middle of the cake.
Add the second layer of cake and repeat the above steps using the remaining lemon curd.
Next, add the final layer of cake on top.
Use your piping bag to fill in any gaps between your 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. Do not mix your crumb coating frosting back into your icing if it has cake debris in it.
Refrigerate the cake for 20 minutes.
Proceed to frost the top and sides of the cake using your offset spatula. Once the sides of the cake are covered, use you icing smoother to remove any excess frosting.
Use remaining frosting to pipe the florets on the top of the cake using an Ateco 846 tip (large open star).
Press any remaining toasted coconut into the bottom edges of the cake or sprinkle over the top.