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!INGREDIENTSFor cupcakes:1 1/2 cups flour1 1/2 teaspoons baking powder1/2 teaspoon salt2 large eggs2/3 cup sugar1 1/2 sticks unsalted butter, melted2 teaspoons vanilla extract1/2 cup milk3/4 cup Lucky Charms Marshmallows1/2 cup gold dragee ballsFor frosting:1 1/2 cups unsalted butter3 cups powdered sugar, sifted1-2 tablespoons heavy whipping cream1 tablespoon vanilla extract1/4 teaspoon saltGreen food coloringRainbow sour candy beltsDIRECTIONSTo make cupcakes: Preheat oven to 350°F. Line a cupcake pan with a dozen cupcake liners.Whisk together the flour, baking powder, and salt in a mixing bowl. In a separate bowl, beat together the eggs and sugar, adding in the butter and vanilla. Add the dry ingredients and milk in small additions, alternating between wet and dry until combined. Pour batter into cupcake liners, bake for 20 minutes, and let cool for 10 minutes.Once the cupcakes have cooled, use a knife to cut out the center of each cupcake, about 1 inch deep. Trim down the bit of cake you removed and save just the top. Fill each cupcake with equal parts marshmallows and gold dragee balls, about 1 tablespoon of each. Cover the hole with the cake you saved from earlier.To make the frosting: Mix butter and powdered sugar until combined. Add heavy whipping cream, vanilla, and salt and mix until smooth. Divide the frosting, leaving 1/3 white and folding in green food coloring into the other 2/3.Pipe the green frosting onto the cupcakes. Top with half of a rainbow belt and two white buttercream clouds on either end. Enjoy!POPSUGAR Food shares delicious recipes, tutorials, kitchen tips and tricks, and everything else you need to start cooking ... and eating! Hosted by Brandi Milloy, POPSUGAR Food shares easy-to-follow recipes, demos, and time-saving kitchen hacks on our show Get the Dish, and recreate the latest food crazes and invent new ones on Eat the Trend. Get the scoop on how to make everything from Cronuts to ramen burgers to vanilla cupcakes and beyond!Subscribe to POPSUGAR Food!http://www.youtube.com/subscription_center?src_vid=wNSZWHtiGek&add_user=popsugartvyumCheck out the rest of our channel:https://www.youtube.com/user/popsugartvyumFor more Brandi, follow her here:Instagram: https://instagram.com/brandimilloyTwitter: https://twitter.com/brandimilloyFaceboook: https://www.facebook.com/OfficialBrandiMilloyYouTube: https://www.youtube.com/user/BrandiMilloy