Preheat oven to 350°F (175°C). Grease a 13×9-inch baking pan with nonstick spray and set aside.
In a large mixing bowl, combine cake mix, water, cherry juice, canola oil, egg whites, almond extract, and food coloring. Beat on medium speed for 2 minutes until smooth.
Pour batter evenly into prepared pan. Bake for 30–35 minutes, or until a toothpick inserted in the center comes out clean. Cool completely.
For the buttercream, beat softened butter for 2–3 minutes until creamy. Gradually add sugar, mixing after each addition. Add vanilla, salt, and milk until fluffy.
Frost cooled cake evenly with vanilla buttercream. Garnish with cherries or sprinkles, slice, and serve.
