Red food coloring paste such as Wilton brand or you can use a tube of store bought red frosting.
Instructions
Preheat oven to 350°F. Use 20 cupcake liners and place in muffin pans. Set aside.
Prepare cake mix according to package instructions. Divide batter equally into the 20 cupcake liners. Bake for 22-24 minutes or until a toothpick inserted into the middle of a cupcake comes out clean. Let cool completely.
Buttercream frosting
Beat softened butter on medium speed with an electric or stand mixer. Beat for 3 minutes until smooth and creamy. Add powdered sugar, cream, and vanilla extract with the mixer running. Increase to high speed and beat for 3 minutes. Reserve one cup of frosting and color it red. Use remaining white frosting to frost the cupcakes. Create a dome shape with the frosting and smooth with an offset spatula. Scoop red frosting into a pastry bag fitted with a #3 pastry tip. (Or you can use a tube of store bought red frosting, preferably with a small round tip.) Pipe baseball thread design onto cupcakes. Refrigerate for 1-2 hours, if you have time, so the icing can set.