Yogurt Sheet Cake

Directions

1. 1
   Preheat oven to 350A°F with rack in middle. Butter a 9x13 cake pan, then line bottom with a rectangle of parchment paper and butter parchment. Dust with flour, knocking out excess.
2. 2
   Sift together cake flour, baking powder, baking soda, and salt.
3. 3
   Beat together butter, sugar, and vanilla with an electric mixer at high speed until pale and fluffy, 3 to 5 minutes.
4. 4
   Beat in eggs, 1 at a time, at medium speed.
5. 5
   At low speed, mix in flour mixture in 3 batches, alternating with yogurt, beginning and ending with flour mixture, and mixing until just combined.
6. 6
   Spread batter evenly in pan and rap pan on counter several times to eliminate air bubbles.
7. 7
   Bake until cake pulls away from sides of pan and a wooden pick inserted in center comes out clean, 35 to 45 minutes. Cool in pan 10 minutes, then run a knife around edge. Invert onto a rack and discard parchment. Cool completely, about 1 hour.
8. 8
   When cake is cool, stir together confectioners sugar, corn syrup, cream, and vanilla until smooth.
9. 9
   Put cake on a platter and spread icing on top in a thick layer, letting it run down sides. Let icing set at least 15 minutes.