Step 1: Prepare the Cupcakes

1. Preheat oven to 350°F (175°C) and line a cupcake tin with paper liners.
2. In a bowl, whisk together flour, baking powder, and salt. Set aside.
3. In a large bowl, beat butter and sugar until light and fluffy.
4. Add eggs one at a time, beating well after each addition. Stir in vanilla extract.
5. Alternate adding the dry ingredients, buttermilk, and Grape Crush soda, mixing until just combined.
6. Add purple food coloring if desired for a vibrant look.
7. Divide the batter evenly into the cupcake liners, filling each about ⅔ full.
8. Bake for 18-22 minutes, or until a toothpick inserted in the center comes out clean.
9. Let cupcakes cool completely before frosting.

Step 2: Make the Grape Buttercream Frosting

1. In a large bowl, beat butter until smooth and creamy.
2. Gradually add powdered sugar, mixing until well combined.
3. Pour in Grape Crush soda and vanilla extract, then mix until fluffy.
4. Add purple food coloring if desired.

Step 3: Frost & Decorate

1. Pipe or spread the frosting onto cooled cupcakes.
2. Garnish with grape candy, sprinkles, or a drizzle of grape syrup for extra flavor.