Fiorella's Cucina Toscana Polenta Cake

Source: Fiorella's, Orlando, Florida

1 cup, plus 1/2 teaspoon sugar
1/2 pound unsalted butter, softened
4 egg yolks, at room temperature
2 teaspoons finely grated orange zest
1 teaspoon finely grated lemon zest
2 vanilla beans or 1 teaspoon pure vanilla extract
1 1/3 cups natural almonds
1 cup yellow cornmeal or coarse polenta
1/2 cup cornstarch
1 teaspoon baking powder
8 egg whites, at room temperature
4 teaspoons confectioners' sugar
Sweetened whipped cream

Heat oven to 325 degrees F. Generously butter 1-inch deep 8-inch square baking pan.

Combine butter, yolks, zests and 1 cup sugar. Scrap seeds from vanilla bean into mixture. Beat on high until creamy, 2 minutes.

In food processor, finely grind nuts with cornmeal/polenta, cornstarch and baking powder.

Beat egg whites with 1/2 teaspoon sugar until soft peaks form. Fold dry ingredients and 1/2 of egg whites into butter mixture; then fold in remaining egg whites until just incorporated. Scrape batter evenly into pan. Bake 30 minutes, or until top is golden and pick inserted in center comes out clean.

Cool in pan on rack 10 minutes. Invert cake on rack; cool completely. Sprinkle with confectioners' sugar.