Preheat oven to 350°. Line a cupcake tin with paper liners and set aside.

1. Whisk together flour, sugar, baking powder, baking soda and salt together.

2. Add in the cubed butter and mix for 2-3 minutes or until mixture looks very crumbly.

3. In a separate bowl, whisk the buttermilk and eggs together, then add into flour mixture and mix until smooth.

4. Add in the oil, greek yogurt and vanilla and mix until just incorporated and no bumps are noticeable. If there are a few, that's olay. Don't over mix.

5. Separate your batter with an ice cream scoop into 6 different bowls, 2 scoops each. Using your food coloring, make each bowl of batter a different color of the rainbow until your desired color is achieved.

6. Spoon a layer of the batter starting with red into each liner, making sure to coat the entire bottom. Repeat this step with each of the colors, layering on top of each. Fill the liners ⅔ full.

7. Place cupcakes into your preheated oven and bake for 14-16 minutes or until a toothpick comes out clean.

8. Let them cool for 2-3 minutes in the pan and then take out and let them finish cooling on a wire rack or counter. While they are cooling, prepare your frosting.

1. In the bowl of your stand mixer, set with a whisk attachment, beat egg whites, corn syrup and salt together for about 3-5 minutes until there are stiff peaks formed.

2. At about 2 minutes slowly add your sugar in while mixer is running.

3. Once stiff peaks are formed, add in vanilla and mix until incorporated.

4. Once your cupcakes are COMPLETELY cooled, spoon your frosting into a zip top bag and cut off one corner. Pipe the frosting onto your cupcakes and garnish with some sprinkles, if desired.