Preheat your oven to 350Β°F (175Β°C). Lightly spray a 12x17 inch rimmed baking sheet with nonstick baking spray, then line it with parchment paper. Gently grease the parchment paper with a dab of butter. Set it aside.
In a medium bowl, beat the egg whites on medium-high speed until they form soft peaks (about 1-2 minutes). Gradually add β
cup of the granulated sugar, continuing to beat on medium-high until shiny, stiff peaks form (another 1-2 minutes). Set these fluffy whites aside.
In another medium bowl, whisk together the egg yolks, vegetable oil, milk, vanilla extract, the remaining β
cup of granulated sugar, and lemon zest until the mixture is smooth and well combined.
In a small bowl, quickly whisk together the flour, cornstarch, baking powder, and salt.
Slowly add the dry flour mixture into the egg yolk mixture, stirring gently until just combined. Be careful not to overmix!
Gently fold the whipped egg whites into the batter until they are fully incorporated, ensuring the batter remains light and airy.
Pour the batter evenly onto your prepared baking sheet. Bake for about 15 minutes, or until the cake is lightly golden brown on top and springs back when touched. Let the cake cool completely on the baking sheet β no need for warm rolling with this simple method!
While the cake cools, combine the sliced strawberries with 1 tablespoon of sugar and 1 tablespoon of lemon zest in a small bowl. This simple step enhances their natural sweetness and brightens their flavor.
In a large bowl, beat the chilled heavy cream on high speed until soft peaks form. Add the sour cream, Β½ teaspoon of vanilla extract, and ΒΌ cup of powdered sugar. Continue beating until the cream holds stiff peaks, creating a stable and luscious filling.
Once the cake is completely cool, gently spread the prepared whipped cream over the entire surface, leaving a 1-inch border around the edges. Evenly scatter the sweetened strawberries over the whipped cream.
Starting from one of the short ends, carefully roll up the cake. As you roll, the parchment paper will naturally peel away. Take your time to achieve a beautiful spiral.
Place the finished cake roll seam-side down on a serving platter. If you like, dust the top with a little extra powdered sugar for a pretty touch. Slice and enjoy this wonderfully light, fruity, and easy-to-make dessert!