Preheat to 350°F. Butter 9-inch-diameter cake pan with 2-inch-high sides; line bottom with parchment. Set aside.

In a stand mixer using the paddle attachment beat together the butter and sugar. When the sugar is mixed in add the eggs.

Combine cornmeal, flour, baking powder, and salt in a bowl; whisk to combine. Whisk buttermilk, lemon peel, and vanilla in another bowl. Add the buttermilk mixture and the flour mixture alternatively to the butter mixture. When the batter has been mixed in completely scrape the batter into pan; spread evenly.

Bake cake until tester inserted into center comes out clean and cake pulls away from sides of pan, about 30 minutes.

Remove from oven and run a knife around sides of cake. Place rack atop cake in pan. Using oven mitts, hold pan and rack firmly together and invert cake onto rack. Remove pan from cake. While cake is still very hot, spread glaze by spoonfuls onto cake. Cool completely. Serve with a fine sprinkling of confectioners sugar.