01 - Preheat oven to 325°F. Line bottom of 8-inch round cake pan with parchment paper, leaving sides ungreased.
02 - Whisk together flour, sugar, baking powder, and salt in a medium bowl until evenly distributed.
03 - Whisk egg yolks, Greek yogurt, vegetable oil, vanilla extract, and lemon zest in a large bowl until smooth and creamy.
04 - Add dry ingredients to wet mixture and stir gently until just incorporated, avoiding overmixing.
05 - Beat egg whites in a clean bowl with electric mixer until stiff peaks form, ensuring maximum volume.
06 - Gently fold one-third of beaten egg whites into batter to lighten. Carefully fold in remaining whites, preserving air pockets.
07 - Pour batter into prepared pan and smooth top. Bake for 35-40 minutes until golden and toothpick inserted in center comes out clean.
08 - Let cake rest in pan for 10 minutes. Run knife around edges, invert onto wire rack, and cool completely. Dust with powdered sugar before serving.