Step 1

Position an oven rack to the lowest level and preheat the oven to 325F.

Step 2

In a large bowl, sift together the flour, sugar, baking powder, and salt. In a medium bowl, whisk together egg yolks, water, oil, and vanilla until pale and frothy, about 30 seconds. Add egg yolk mixture to flour mixture, whisking until well combined.

Step 3

In the bowl of a stand mixer fitted with a whisk attachment, beat the egg whites and cream of tartar on medium-high speed until stiff peaks form, about 6 minutes. Fold one-fourth of the egg whites into the flour mixture, until just combined. Gently fold in the remaining egg whites. Spoon batter into an ungreased 10-inch tube pan. Run a butter knife gently through the batter to release any potential air pockets.

Step 4

Bake on the lowest rack for 1 hour or until a wooden pick inserted in the center comes out clean. (Take should spring back when gently poked with your finger.) Immediately invert the pan onto a wire rack and let the cake cool completely in the pan. When cooled, gently run a knife around the edges of the pan to release the cake. Place the cake on a cake stand and garnish with confectioners’ sugar, if desired.