Place cupcake liners in muffin tin. Spray lightly with cooking spray.
Add dry ingredients - flour, sugar, baking powder, baking soda, and salt - to a large bowl and whisk to combine.
Add wet ingreidents - milk, oil, egg, and vanilla - to the dry ingredients and whisk until well combined. Carefully pour in the boiling water and whisk until well combined and the batter is smooth.
Evenly distribute the cake batter into the cupcake liners. Each liner should be about 1/2 full.
Place in the oven and bake until a toothpick inserted in the center comes out clean, about 25 minutes.
Remove from the oven and allow to cool about 5-10 minutes in the pan. Then carefully remove the cupcakes from the pan and transfer them to a wire rack to cool completely.
Once cooled, frost the cupcakes and serve.
Notes
Nutritional information is for the vanilla cupcakes as listed in the recipes. The frosting is not included in this information.
Storage Instructions
Unfrosted Cupcakes:
Make certain the cupcakes have completely cooled before covering them. Any bit of heat left in the freshly baked cupcakes will cause condensation.
After they are completely cool, store them in a container with an airtight lid, like a cake carrier or a large, deep storage container with an airtight lid. They can be stored on the countertop, out of direct sunlight, and at room temperature for up to two days.
If you bake the cupcakes the night before your event and need to store them, it's easier to store them Unfrosted for 1-2 days. Then frost the cupcakes just prior to serving.
Unfrosted cupcakes made according to this recipe do not require refrigeration. If you need to store them in the refrigerator due to summer heat or an added ingredient, they should remain fresh for 3-4 days in the refrigerator when stored properly in an airtight container.
Frosted Cupcakes:
Frosted cupcakes should be stored in an airtight container, such as a cake carrier or a large, deep storage container with an airtight lid. They should stay fresh in the storage container for 3-4 days.
The frosting on the cupcakes will determine if they require refrigeration. A good rule of thumb is if you add items to the cupcakes or to the frosting that requires refrigeration on its own, those cupcakes will also require refrigeration.
Freezing Instructions
Freeze Unfrosted Cupcakes:Freezing the cupcakes unfrosted is the best option if possible.
Make sure the cupcakes are completely cooled. Once the cupcakes have cooled completely, wrap each unfrosted cupcake well in plastic wrap.
Place each individually wrapped cupcake into a freezer-safe, air-tight zip-top bag or container. Store in the freezer for up to 3 months.
Freeze Frosted Cupcakes:
Put the frosted cupcakes in a single layer without covering them on a baking sheet or freezer-safe dish.
Pre-freeze the frosted cupcakes by placing them in the freezer to flash freeze them to "harden" the frosting for about 1 hour until frozen.
Wrap each flash-frozen frosted cupcake individually with plastic wrap.
Use a sturdy and deep airtight container for freezing frosted cupcakes. Place each individually wrapped frosted cupcake into the container and seal it with an airtight lid.
Store in the freezer for up to 3 months.
Defrost Frozen Cupcakes
Remove from the freezer, remove the plastic wrap, and let thaw at room temperature.
Allow them to reach room temperature before applying the frosting. You should also let the frozen frosted cupcakes come to room temperature before serving them too.