Preheat oven to 350 degrees. Line a jelly roll (10x15”) pan with foil and spray with cooking spray (use the one with flour, or flour the pan after spraying, to avoid sticking.)
In a mixing bowl or stand mixer, beat the eggs at high speed for 2 minutes, until frothy and dark yellow. Mix in sugar, lemon juice, and zest.
In a separate bowl, whisk together salt, baking powder, and flour. Add into wet ingredients and mix at low speed until just blended.
Spread the batter into the prepared pan.Since the batter is a very thin layer, you will need to use a wooden spoon or spatula to spread it to all the corners of the pan. Bake for 9-11 minutes.
While the cake is baking, set a large, clean kitchen towel out on a large work surface. Sprinkle liberally with powdered sugar (about 1/4 cup). As soon as the cake comes out of the oven, turn it over on the kitchen towel sprinkled with powdered sugar. Remove foil carefully.
Working from the short end, fold the edge of the towel over the cake. Roll tightly, rolling up the cake into the towel. Let cool completely while rolled, at least one hour.
While the cake is cooling make the filling. Beat the heavy whipping cream and powdered sugar until stiff peaks form. Stir in the lemon extract. Refrigerate until ready to use.
When cake is cool, carefully unroll the towel. Spread the lemon cream over the cake, as evenly as you can. Roll the cake again, gently but tightly (and withouth the towel this time.) Wrap in plastic wrap to prevent drying out, and refrigerate for at least one hour, up to overnight.
When ready to serve, sprinkle powdered sugar on top, slice the cake and serve with berries on the side, if you like!