Ever wonder what's at the end of the rainbow? Now you can find out with these St. Patrick's Day surprise-inside cupcakes (hint: it's a lot of gold and marshmallows). These fluffy cupcakes are packed with sweet surprises and topped with a lightly sour rainbow strip. These treasures are sure to liven up your St. Patrick's Day party! For more recipes ideas, try our green red velvet cake and our own version of McDonald's Shamrock Shake.