Preheat oven to 350° and place paper baking cups into 24 regular-sized muffin cups.

In a medium bowl, mix flour, baking powder, and salt.

In a large bowl, cream sugar, butter, and eggs.

Next, add vanilla extract.

On a low speed, alternate blending in dry mixture and milk.

Drop in 6 drops of red food coloring to every 1 drop of yellow until watermelon pink color is achieved. You may need more red, depending on how dark you want to make it.

Hand blend in chocolate chips. These will be your watermelon seeds.

Fill each muffin cup up about 2/3 full and bake for 20-25 minutes until an inserted toothpick comes out clean. Cool thoroughly before frosting.

Beat butter with an electric mixer at medium-high speed until creamy.

Gradually beat in sugar until smooth.

Beat in watermelon flavoring and gradually add milk until desired consistency is reached.

Separate about 2 tablespoons of frosting into a separate small bowl.

In bigger bowl (with your original frosting), add green food coloring ONE DROP at a time until a light green watermelon rind color is achieved.

Spoon the different colored green frostings into 2 icing bags. Snip the ends, then place into 1 large icing bag together. Pipe the frosting onto the cupcakes in a swirl.