• Pre-heat oven to 350 degrees.
• In the bowl of a stand mixer or in a large bowl with a hand mixer, cream butter and sugar together, until light and fluffy.
• In a separate medium-sized bowl, whisk together flour, baking powder, and salt.
• Slowly mix the dry ingredients into the butter and sugar mixture, alternating with the whole milk.
• In another separate medium-sized bowl, whisk egg whites with a hand mixer or whisk until stiff peaks form.
• Gently fold the egg whites into the batter, until just blended.
• Separate batter into three bowls. Mix raspberry extract into one bowl, mix orange extract into another, and mix fresh lime juice into the third.
• In a lined cupcake pan or cupcake pan sprayed with cooking spray, fill each cavity about ¾ of the way full with the batter from each bowl.
• Bake at 350 degrees for about 15-17 minutes, until a toothpick comes out clean.
• Cool cupcakes in tins for a few minutes before removing to wire racks to cool completely.
• Using the Wilton ColorSwirl 3-Color Coupler and a 1M pastry tip or following this tutorial, frost cupcakes with sherbet buttercream.

Sherbet Buttercream Frosting

• In the bowl of a stand mixer or in a large bowl with a hand mixer, beat the butter until creamy.
• Slowly blend in the confectioners' sugar, cup by cup until well-combined. Mix in milk.
• Separate buttercream frosting into three separate bowls.
• If you're using real raspberries instead of extract, place them in a saucepan over medium heat, stirring with a wooden spoon until they break down into a sauce. Continue to cook until sauce thickens. Remove from heat and pour through a fine mesh strainer. Press on seeds with wooden spoon to extract juice.
• Mix 2 t fresh raspberry juice (or raspberry extract) into frosting in one bowl, mix orange extract into another, and mix fresh lime juice into the third.
• Mix orange food coloring into orange extract frosting and green food coloring into lime extract frosting. If you used raspberry extract instead of fresh or frozen raspberries, mix red food coloring into raspberry frosting.
• If frosting is too stiff, more milk can be added 1 tsp at a time.