1-First Step: Preheat and Prepare the Pan Begin by preheating your oven to 350°F and spraying a baking sheet with nonstick spray. Line it with parchment paper and grease the parchment with butter. This sets up a non-stick surface that makes rolling the cake simple and prevents sticking.

2-Second Step: Whip the Egg Whites In a clean bowl, beat the 4 egg whites at room temperature on medium-high speed until soft peaks form, which takes about 1 to 2 minutes. Add one-third cup of the granulated sugar and continue beating until stiff peaks form, another 1 to 2 minutes. Set this aside as it will give your cake its airy lift.

3-Third Step: Mix the Egg Yolk Batter In a separate bowl, whisk together the 5 egg yolks, 2 tablespoons vegetable oil, 3 tablespoons whole milk, 1 teaspoon vanilla extract, the remaining two-thirds cup granulated sugar, and 1 tablespoon lemon zest until well combined. This creates the wet base of your cake.

4-Fourth Step: Combine Dry Ingredients In another bowl, whisk the ¾ cup all-purpose flour, 2 tablespoons cornstarch, 1 teaspoon baking powder, and ¼ teaspoon fine sea salt. Stir this dry mixture into the wet egg yolk batter until just combined, being careful not to overmix.

5-Fifth Step: Fold and Bake Gently fold the whipped egg whites into the batter until fully incorporated to keep the air in. Pour the batter onto your prepared baking sheet and spread it evenly. Bake for 15 minutes or until the top is lightly browned, then let the cake cool completely on a wire rack.

6-Sixth Step: Prepare the Filling While the cake cools, mix the 1 pound sliced strawberries, 1 tablespoon sugar, and 1 tablespoon lemon zest in a small bowl. In another bowl, beat the 1 cup heavy whipping cream on high until soft peaks form, then add 1 tablespoon sour cream, ½ teaspoon vanilla extract, and ¼ cup powdered sugar. Beat until stiff peaks form for a sturdy filling.

7-Seventh Step: Assemble the Roulade Spread the whipped cream mixture over the cooled cake, leaving a one-inch border around the edges. Sprinkle the strawberry mixture over the cream. Starting from a short end, carefully roll the cake, letting the parchment peel off as you go. Place it seam side down on a plate.

8-Final Step: Finish and Serve Dust the rolled cake with powdered sugar if desired, then slice and serve right away. The total prep time is 15 minutes, cooking takes 15 minutes, and cooling needs about 2 hours, making the whole process simple for any home cook. Remember, preparation time is 30 minutes excluding cooling, so plan ahead for the best results. For more baking inspiration, fresh strawberries offer great health benefits of strawberries.