Preheat the Oven: Start by preheating your oven to 150 °C (300 °F). While it warms up, prepare a cupcake mold by lining it with paper capsules.
Prepare the Base: In a mixing bowl, whisk together the oil, sifted flour, and condensed milk until smooth. Then, add the egg yolks and the whole egg, mixing well until you reach a homogeneous batter.
Make the Meringue: In a separate bowl, beat the egg whites with lime juice until foamy. Gradually add the sugar, continuing to whip until you achieve firm peaks—this is where your cupcakes get their fluffy texture!
Combine and Bake: Gently fold the meringue into the batter, using enveloping movements to retain the airiness. Fill your cupcake molds up to 3/4 full with the batter and then bake for about 25-30 minutes. You’ll know they’re ready when they turn golden, and a toothpick inserted in the center comes out clean.
Cool and Serve: Allow the cupcakes to cool completely before removing them from the mold. Enjoy these delightful treats as they are, or dress them up with a glaze!