1tspcoarse Kosher salt(if using table salt, use half the amount)
1 ½cupswhole buttermilk,lukewarm
2large whole eggs
2large egg whites
Apricot Almond Filling & Buttercream
6ozalmond pastry filling(not almond paste)
1jar (13 oz)apricot preserves
1 ½cupsunsalted butter,softened to room temperature
⅛tspcoarse Kosher salt(if using table salt, use half the amount)
fresh apricots, sliced, for garnish
Preheat the oven to 350F, and grease the bottoms of three 8-inch cake pans with non-stick spray.
In a large bowl, sift together the flour, sugar, baking powder and salt. Whisk in the poppy seeds.
Separately, whisk together the buttermilk, melted butter, oil, eggs, egg whites, almond extract and vanilla extract.
Add the wet ingredients to the dry, and whisk until combined and smooth, about 10-15 seconds. Divide the batter evenly between the greased pans.
Bake the cakes on the center oven rack until a cake tester inserted in the center comes out clean, and the tops spring back when lightly touched, about 25-30 minutes.
Set the pans on a cooling rack, cover loosely with a clean kitchen towel, and cool completely before frosting.
Remove the cooled cakes from the pans, and use a sharp knife to carefully split the cakes so you have six thin layers.
Measure out 1/2 cup of the apricot preserves and set aside to reserve for the buttercream.
Place one layer of cake on a cake board. Spread evenly with 1/3 of the remaining apricot preserves. Stack the second layer of cake on top, and spread with 1/2 of the almond pastry filling. Repeat with the third layer of cake, 1/3 of the apricot preserves, the fourth layer of cake, 1/2 of the almond pastry filling, the fifth layer of cake, 1/3 of the apricot preserves, and then the last layer of cake. In total, you will have six layers of cake, alternately filled with 3 layers of apricot preserves and 2 layers of almond pastry filling.
Use a small food processor to puree the reserved 1/2 cup of apricot preserves.
In the bowl of your stand mixer fitted with the whisk attachment, beat the preserves and butter until smooth.
With the mixer on low, gradually add the powdered sugar and meringue powder, mixing to combine. Add the vanilla and almond extracts and the salt. On medium speed, whip for 4-5 minutes, scraping the bowl occasionally, until very light and fluffy.
Frost the cake with a thin crumb coat of buttercream to seal the crumbs and fillings in, and refrigerate for 20-30 minutes. Frost the cake with the final coat of buttercream.
If you like, tint some of the buttercream with a few drops of orange and yellow gel food coloring for an apricot color. Swirl the tinted buttercream on top and around the sides of the cake for a pretty watercolor effect.
Garnish with fresh apricot slices.
Leftover cake should be stored in an airtight container at room temperature for up to 3 days.