For the batter: Beat the sugar and egg yolks in a medium bowl with a hand mixer on medium-high speed until pale. Add the milk and oil and beat until incorporated. Add the flour, baking powder and salt and beat until combined, about 3 minutes. Beat in the vanilla paste and lemon zest until combined. Clean the beaters.
For the meringue: Using the hand mixer with the clean beaters, beat the egg whites and one-third of the sugar in another medium bowl on medium-high speed until the sugar is dissolved. Gradually beat in the remaining sugar until stiff peaks form. Fold one-third of the meringue into the batter with a spatula. Fold in another third and then the remaining third until all the meringue is incorporated.
Soak a paper towel with oil and wipe the bottom of a medium nonstick skillet to lightly coat; heat over medium low. Add 1/3 cup of the batter to the skillet. Cover and cook for 5 minutes. Remove the cover, flip the pancake over gently and cook, uncovered, until just set and golden brown, another 5 minutes. Serve hot. Repeat with more oil and the remaining batter.