Roman Breakfast Cake (Dairy Free)

1. Center and rack in the oven and preheat to 350 degrees. Generously oil or butter a 10-inch tube pan or cake pan, dust the interior with flour, and tap out the excess. Be assiduous - this cake is a sticker. Alternatively, use baker's spray. 2. Whisk together the flour, baking powder and 1/4 teaspoon salt; set aside. 3. Separate the eggs whites from the yolks and set the yolks aside. Using a mixer with a whisk attachment, beat the egg whites and the remaining 1/4 teaspoon salt on medium high speed until they form firm glossy peaks. If you are using a stand mixer, scrape the whites into another bowl. No need to rinse the mixer bowl. 4. Zest the 2 lemons. Juice one of the lemons and set the juice aside. 5. Fit the mixer with the paddle attachment. Put the sugar and lemon zest in the mixer bowl, and rub them together until the mixture is fragrant. Add the yolks, and beat on medium speed for 3 minutes, scraping the bowl as needed. The batter will be thick, pale and shiny. 6. With the mixer on medium, pour in the oil and continue to beat for another 3 minutes. Mix in the lemon juice vanilla and lemon oil, if using, then scrape the bowl well. Turn off the mixer, add the dry ingredients and pulse the mixer a few times to start incorporating them. Work on low until the flour is blended into the batter, which will be smooth and thick. 7. Beat the white briskly with a whisk (to re-stiffen them and incorporate any liquid in the bowl). Scrape a few spoonfuls of eggs whites over the batter and use a flexible spatula to stir them in and to lighten the batter. Turn the rest of the eggs whites into the bowls, and fold them in gingerly. If you are using the berries, gently fold them in just before the whites are fully incorporated. Scrape the batter into the baking pan and level the top. 8. Bake the cake for 45 to 50 minutes until lightly browned; a tester inserted deep into the cake should come out clean. Transfer to a rack and wait 5 minutes. Run a blunt knife around the edges of the pan to loosen the cake, invert onto the rack and unmold. Cool to room temperature. Dust with confectioner's sugar, if you like.