1-First Step: Preheat oven to 350°F. Spray a baking sheet with nonstick baking spray, line with parchment paper, and grease the parchment with butter.

2-Second Step: Beat egg whites in a medium bowl on medium-high speed until soft peaks form (1-2 minutes). Add 1/3 cup sugar and beat until stiff peaks form (1-2 more minutes). Set aside.

3-Third Step: In another medium bowl, whisk egg yolks, 2/3 cup sugar, oil, milk, vanilla extract, and lemon zest.

4-Fourth Step: In a small bowl, whisk flour, cornstarch, baking powder, and salt. Stir dry ingredients into wet ingredients just until combined.

5-Fifth Step: Fold egg whites gently into the batter until fully incorporated. Stop as soon as you see no streaks so you don’t deflate the foam.

6-Sixth Step: Pour batter onto prepared baking sheet and bake for 15 minutes until the top is lightly browned.

7-Seventh Step: Let cake cool completely. This is the make-or-break moment. If you roll warm cake, it can crack and tear.

8-Eighth Step: For the filling, combine strawberries with 1 tablespoon sugar and 1 tablespoon lemon zest. Let sit to release juices.

9-Ninth Step: Beat heavy cream until soft peaks form. Add sour cream, vanilla extract, and 1/4 cup powdered sugar, then beat until stiff peaks form.

10-Tenth Step: Spread whipped cream on cooled cake, leaving a 1-inch border around edges, then scatter strawberries on top.

11-Eleventh Step: Starting at the short end, roll the cake gently, allowing parchment to fall away as you roll. Go slow, and keep the pressure light.

12-Twelfth Step: Place seam side down and dust with powdered sugar if desired.

13-Final Step: Slice and serve. For clean slices, wipe your knife between cuts if needed.