Preheat oven to 350 degrees. In a medium bowl, whisk together cake flour, baking powder, baking soda, and salt. Set aside.

Add the softened butter into the bowl of your stand mixer and beat until light and creamy. About 2 minutes. Gradually add in sugar and beat for another 3-5 minutes. Beat in vanilla and egg yolks until incorporated.

Continue beating the butter mixture on medium speed. Add ⅓ of flour mixture, beat a few seconds to incorporate, then add ½ of yogurt. Repeat until all the flour mixture and yogurt has been mixed in.

Beat the egg whites until stiff peaks form in a separate bowl with hand-held beaters. Or you could transfer the contents of your stand mixer bowl to another mixing bowl and clean your bowl and whisk attachment to whisk the egg whites.

Gently fold in egg whites in the cake batter. The batter is a little thick, so don't be afraid of putting a little muscle into mixing your egg whites in.

Spray cake pans with non stick spray and line bottoms with parchment paper. I trace and cut them out with a scissor. Divide the cake batter evenly in the pans. Use an small offset spatula to help spread and level the cake batter. Bake for 20-22 minutes until golden and test for doneness with a toothpick. Once done, allow to cool in the pans for 5 minutes. Carefully remove cakes from the pans and allow to completely cook on a wire rack. Use a knife to help loosen the edges of the cake.

Make your buttercream by beating softened butter in your stand mixer until light and creamy. Gradually add in powdered sugar and mix until fluffy, about 5 minutes. Add in tahini, ground black sesames, and salt. Beat for another 2 minutes. Transfer buttercream into a piping bag with a medium round tip if you're going to attempt to pipe some designs.

Start assembling the cake by layering buttercream on top of your first tier. Use an offset spatula to help level the buttercream. Add another a layer of cake and repeat until all layers are stack. Use a dough scraper to check if the edges are straight. Frost the entire cake with your remaining buttercream. Decorate with additional piping or extra black sesame seeds!

Slice and enjoy!