• Read ALL of the instructions and plan your time. Gather your equipment and ingredients.
• Preheat the oven to 350°F (350 degrees Fahrenheit).
• Spray the muffin tin with cooking spray or wipe with a paper towel dipped in oil. You can also use paper cupcake liners. You don't have to oil the paper liners, but it helps them to peel off the cake.
• Open the boxes of caked mix and pudding mix and place both into the large bowl.
• On the rim of a medium size bowl, crack open each egg and carefully pull apart the shell to let the egg yolk and egg white drop into the bowl. Scramble (beat) them until they are combined.
• In the other medium sized bowl, add together the sour cream, cooking oil and water. With a fork or whisk, blend together until there are no lumps.
• Add the scrambled eggs and the sour cream mixture into the large bowl with the cake and pudding mix. Stir until all the wet and dry ingredients are combined into a batter.
• Carefully place batter into each cup of the tin. Fill the cup half way to leave room for the batter to rise. There should be enough batter to make 24 cupcakes.
• Place the tins into the oven and set the timer for 12 minutes.
• When the cupcakes have finished baking, remove the tins from the oven and place on the kitchen counter to cool.

Vanilla Marshmallow Fluff Icing

• Use an electric mixer to beat the butter until it is light and creamy.
• Add the marshmallow fluff and beat until combined. (See the instructions below for how to make homemade marshmallow fluff).
• Add the vanilla extract and mix to combine.
• On a slow mix setting, add the powdered sugar, incorporating each addition before adding the next. Stop the mixer and use a silicone spatula to scrape down the sides of the bowl if it is going up the sides and not mixing. If the mixing blade is going too fast or you put too much in at a time, the powdered sugar will fly out of the bowl and all over the place. You want the sugar in the icing and not on the counter!
• Add salt. (Optional). If you used unsalted butter, you can add ½-1 teaspoon depending upon your preference. Salt is good for balancing the sugar, but once there is too much salt, it is hard to correct.
• Add the heavy cream a tablespoon at a time. If the icing is too thick or dry after adding 3 tablespoons, you can add more to loosen it.
• If the icing is too loose, it will be spreadable, but not hold its shape if you are using a piping bag. You can always add more powdered sugar if the icing is to thin.
• Use a knife to spread icing OR place icing into a piping bag fitted with the tip of your choosing.

Homemade Marshmallow Fluff Using a Double Boiler

• Put water into the bottom pot of the double boiler and place the cooking pot on top. Bring to a boil.
• Place marshmallows in the top of the double boiler. Let melt (10-15 minutes). They should be white when melting. If they start to brown on the bottom, remove the upper pot from the boiling water and let cool before placing back over the boiling water. STIR SLOWLY as the marshmallows get close to being fully melted. Vigorous stirring will cause the confection to stick to the sides of the pot and it is impossible to move back to the center. This is because the sugar begins to cool and stick to the pot. You want to keep the confection warm. Don't forget to use a pot holder!
• Add the corn syrup to the center of the melted confection, 1 tablespoon at a time. Stir quickly to incorporate. Add corn syrup until you are satisfied with the consistency of the fluff. It should be shiny, smooth and elastic.
  
• At this point, you can store the fluff in a plastic container to use later. The warmer the fluff, the easier it is to remove from the pot. It cools quickly, so you have to work fast!
• If you are going to use the fluff right away, it may make the butter break down and melt because it is too warm. Add it in small batches to avoid overheating the mixture. Beat to combine.

Homemade Marshmallow Fluff using a Microwave

• Put marshmallows in a GLASS microwave safe bowl. Cover with a microwave safe food cover or paper towel to avoid sticky splatter. Using a low setting and short time settings of 20-40 seconds, slowly melt the marshmallows. Microwaves vary in heat output, so it's best to start with shorter time. Be patient. It can take longer than you think. Be careful not to have the heat setting too high or the sugar will scorch.
• When the marshmallows have melted enough to stir, add the corn syrup. Don't forget to use oven mitts!

Homemade Marshmallow Fluff using an Oven

• If you are a young or inexperienced baker and worried that using a double boiler or microwave is not safe, you can use your oven to melt the marshmallows. Set it to a low temperature, 275° - 325°. Put the marshmallows in an oven proof glass or ceramic bowl and place in the oven. Be sure to check the marshmallows often to make sure they aren't burning. When they are melted, remove the bowl from the oven and stir in the corn syrup. Don't forget to use oven mitts!

Icing with a Piping Bag and Tip

• The tip opening should be on the larger side to allow even flow. You may need to refrigerate the icing to make it firmer to pipe. If you don't have a piping bag, use a plastic food storage bag. Slice the end off of a corner and place the tip into the opening. You can also pipe without a tip. You may have to experiment with the size of the opening to get the flow and control that you want.
• Filling a piping bag can be awkward and messy. Here's a tip: With the tip inserted in place, put the bag into a tall drinking glass with a wide rim or a wide mouthed canning jar. Fold the edges of the bag over the sides and spread the plastic open inside the glass/jar. Use a silicone spatula to spoon the icing from the bowl. Fill carefully and then gather up the sides. Don't overfill. Twist and push the icing to the bottom of the bag.
• When icing, keep a firm consistent pressure on the bag by keeping it tightly twisted shut.