1. Prepare Oven and Muffin Tin:

• Preheat the oven to 350°F (175°C).
• Line a standard-sized muffin tin with cupcake liners. Set aside.

2. Mix Wet Cupcake Ingredients:

• In a medium size (2-3 quarts) mixing bowl, add the room temperature egg whites, vegetable oil, and grape soda.
• Use a handheld electric mixer on medium-low speed (or a whisk) to mix these wet ingredients until they are well combined.

3. Combine Batter:

• Lower the mixer speed to low. Add the dry white cake mix and the packet of unsweetened grape drink mix to the wet ingredients.
• Mix on low speed just until the dry ingredients are incorporated and the batter starts to come together. Do not overmix.
• If using, add 2-3 drops of the purple gel food coloring now for a lighter purple, or more (4-6 drops total) for a deeper color. Continue mixing on low speed only until the color is uniform and no streaks remain. Scrape the bowl if needed.

4. Fill Liners and Bake:

• Fill the prepared cupcake liners about two-thirds (⅔) full with the batter. An ice cream scoop can help make them even.
• Place the muffin tin in the preheated oven. Bake for 15 minutes, or until a toothpick inserted into the center of a cupcake comes out clean or with only a few moist crumbs attached. (Recipe notes ovens vary, start checking around 12 minutes).  
• Carefully remove the cupcakes from the muffin tin immediately (or after a minute) and transfer them to a wire cooling rack to cool completely before frosting.

5. Make the Buttercream Frosting:

• Ensure the butter is properly softened to room temperature.
• Using either a stand mixer fitted with the paddle attachment (or whisk, depending on preference) or a large mixing bowl and a handheld mixer, beat the softened salted butter, pure vanilla extract, and pure almond extract together on medium-high speed for 1 to 1 ½ minutes, until the butter is light in color and fluffy. Scrape down the bowl.
• Lower the mixer speed to low. Add the sifted powdered sugar, about 1 cup at a time, alternating with adding a tablespoon of the heavy cream (e.g., Sugar-Cream-Sugar-Cream-Sugar-Sugar). Mix on low until each addition is incorporated.
• Once all the powdered sugar and cream have been added, increase the mixer speed to medium-high. Continue mixing until the frosting is well combined, smooth, and fluffy, about 1-2 minutes more.
• Lower the mixer speed to medium. Add 4-6 drops of purple gel food coloring (or desired amount) and mix just until the color is uniform and no streaks remain.

6. Frost and Decorate:

• Ensure the cupcakes are completely cool.
• Fill a disposable piping bag fitted with your desired shaped tip (like a star or round tip), or a gallon-size Ziploc bag with a corner snipped off, with the purple buttercream frosting.
• Hold the piping bag vertically, about ½ inch above the surface of a cooled cupcake. Use steady, even pressure to gently squeeze the frosting in a spiral pattern, starting from the outside edge and working inwards and upwards, or create simple swirls or dollops.
• If using, immediately sprinkle the frosted cupcakes with the purple sparkling sugar.

7. Serve:

• Serve the Grape Soda Cupcakes and enjoy the fun, fruity flavor! Store leftover frosted cupcakes in an airtight container.