Preheat the oven to @325 degrees F. Prepare your cupcake/muffin pan with cupcake liners.
Zest the key limes for the cupcakes. As the key limes are small and thin-skinned, it is best to zest them before slicing or juicing because once you inflate them by juicing out, it will become nearly impossible to zest them.
Combine oil and sugar in a large bowl.
Mix until well combined. It will take about 2-3 minutes to blend everything together. I find it easier to blend with a stand mixer, but you can use a hand mixer as well. Sift the dry ingredients through a sieve. Sifting dry ingredients helps to aerate the mixture, which is essential for the batter to rise correctly while baking. Sifting also ensures your batter is lump-free.
Add the flour mix to the sugar-oil mix.
Add the remaining ingredients - yogurt, milk, lemon zest, lemon extract, and lemon juice to the mixing bowl - alternate between adding the dry ingredients and the milk to the oil-sugar mixture until thoroughly combined.
Mix the ingredients well. Keep scraping down the sides of the bowl so that the batter is evenly blended.
Divide the batter evenly between the cupcake tin. Fill the cupcake liners about ⅔ to avoid overflowing the batter during baking. The batter puffs during baking, and it needs space to do so.
Bake the key lime cupcakes in a preheated oven (@325 degrees F) for 18-20 minutes or until the toothpick inserted in the middle of the cupcakes comes back clean with just a few crumbs attached.
Allow them to cool in the pan for a couple of minutes, and then remove the cupcakes from the cavity to cool completely on a wire rack.
Soft and airy cupcakes are ready to be devoured.
If you like them frosted, pipe the completely cooled beautiful cupcakes with key-lime frosting. Garnish with lime zest and a wedge, and enjoy!