Step 1

Preheat oven to 350 degrees (175 C) and place an oven rack in the center of the oven.

Step 2

Line the bottom of an 8-inch cake pan with parchment paper to fit (see how-to video above) and lightly brush the bottom and sides of the pan with oil or cooking spray.

Step 3

Whisk the cornmeal, flour, baking powder and salt in a bowl and set aside.

Step 4

Beat the eggs, egg whites and sugar in a heavy-duty stand mixer on medium-high speed 4-5 minutes, until pale and creamy. On low speed, mix in the oil. butter, yogurt, lemon zest and juice.

Step 5

Stir in the dry ingredients until just blended. Pour the batter into the pan and bake 35 - 40 minutes, or until the top feels firm (not hard) and a toothpick inserted in the center of cake comes out clean. Cool in the pan 10 minutes before inverting onto a rack to cool - run a dull knife around the edge of the pan to loosen.

Step 6

Sift powdered sugar over the cake and serve.