Eggnog Sheet Cake

Preheat oven to 350°F (180°C). Using a pastry brush, lightly brush bottom of a 13x9-inch baking pan with baking spray with flour. (Do not brush sides of pan.)

In a large bowl, whisk together flour, 1 cup (200 grams) granulated sugar, baking powder, salt, and nutmeg.

In the bowl of a stand mixer fitted with the whisk attachment, beat egg yolks at medium-high speed until doubled in volume, about 3 minutes. Reduce mixer speed to medium; add melted butter in a slow, steady stream until incorporated. Reduce mixer speed to low; beat in ¾ cup (180 grams) cold water and vanilla. Transfer batter to a large bowl. Thoroughly clean and dry bowl and whisk attachment.

In the bowl of a stand mixer fitted with the whisk attachment, beat egg whites at medium speed until soft peaks form, about 2 minutes. With mixer on low speed, add remaining ½ cup (100 grams) sugar in a slow, steady stream, beating until combined. Increase mixer speed to medium-high; beat until medium peaks form, about 2 minutes.

Using a balloon whisk, gradually fold flour mixture into yolk mixture until combined. Using whisk, fold egg whites into yolk mixture in three additions. Spread batter into prepared pan. Gently tap pan on a kitchen towel-lined counter 2 to 3 times to remove any large air bubbles.

Bake until golden brown and a wooden pick inserted in center comes out clean, 30 to 40 minutes. Let cool in pan on a wire rack for 40 to 45 minutes. Run a sharp knife around edges of pan to loosen cake. Using a small wooden skewer, poke holes all over warm cake. Slowly pour eggnog evenly all over warm cake. Let cool completely in pan on a wire rack. Cover and refrigerate until cold, at least 4 hours, or up to overnight.

Spread Vanilla Whipped Cream onto cake just before serving. Garnish with nutmeg, if desired. Cover and refrigerate for up to 3 days

In the bowl of a stand mixer fitted with the whisk attachment, beat all ingredients at low speed until well combined. Increase mixer speed to medium-high, and beat until medium peaks form, 2 to 3 minutes.