If you have never made your own marble cupcake this will be a fun activity with your kids. Simply take a yellow cake mix and prepare according to the box. In a separate small bowl remove 1-2 cups of batter. Add a few drops of red (or whatever color you want) food color or a package of kool-aid powered drink mix and stir to get the new color. You can get natural food colors if you are concerned with using dye.
Fill your muffin tin 1/2 full with your yellow cake mix and then add 1 spoonful of red batter to the middle of each muffin cup. Using a butter knife swirl the red batter to make a marbled look. Not too much to avoid over mixing. Then bake as the package suggests and ice! You can make these gluten free by using a gluten free cake mix.
Be sure to check out these other Valentine’s Day posts:
Valentine’s Day Treat Box Ideas
Batman Valentine Exchange Box
Handstamped Valentine Cards
Heart Photo Craft Using Cupcake Wrappers
How to Make a Candy Vase
Candy Cane Hearts
How to make a “candy bar cake”
Frugal Handmade Valentine’s
As stay-at-home moms for eight years, Melissa and Shelley know what it takes to live a savvy lifestyle within a budget. Their passion for helping people has expanded their reach from Stockpiling Moms.com to also including speaking engagements, book authors (Savvy Saving Couponing Secrets from the Stockpiling Moms) and conference co-hosts. Melissa and Shelley are best friends who met through 
A spoonfull of Strawberry Jam in the middle is more fun and very tasty!