Begin by gathering out all ingredients and measuring out quantities needed. Preheat your oven to 325 F and prepare cupcake tins. Whip butter, sugar, vanilla extract, and salt together until light and fluffy. Mix together all of the dry ingredients and measure out wet ingredients at this point as well. If your coconut oil is in a liquid state, go ahead and add it to your milk. If not, you can whip it together with the butter.
Continue whipping the butter while you incorporate one egg at a time, mixing until everything comes together. Carefully add in a third of the dry ingredients into the butter mixture. Follow with the milk and then continue alternating in this pattern until the batter is fully mixed. Take care not to create too much gluten at this step as it will lend to a tough cake. Lastly, I added lime zest and juice.
Once everything is mixed together, I actually let the batter sit for about 30 minutes. I found that if I let it sit that the crumb of the cupcake was better and I actually got a better rise out of the batter as well. Try out both methods for yourself to see what works best for you! I baked my cupcakes for about 40 minutes. If you are baking a cake using this recipe, bake for about 50 minutes before checking if the batter is fully baked through. I always like to check by turning on the oven light and looking through the glass as well because sometimes this keeps the baked product from falling.
Once completely baked through, remove from the oven and allow to cool completely before frosting. Enjoy!