Preheat oven to 350 degrees Fahrenheit and lightly spray a baking sheet with non-stick cooking spray.
In a large bowl, whisk the 1 cup softened butter and 1 cup sugar for about 2 minutes or until creamy. Stir in 1 egg, food 1 tablespoon red food coloring, and 1 teaspoon vanilla until completely blended.
Mix in the 2 ½ cups all-purpose flour, 3 tablespoons unsweetened cocoa powder, and ¼ teaspoon salt until combined.
Roll the dough into 1-inch balls and place them 2 inches apart on the prepared baking sheet.
Press a thumb into the center of each cookie to make an indentation, but be careful not to press all the way to the cookie sheet. Bake for 10-12 minutes. Allow to cool on cooling racks.
To make the frosting, whisk the 2 tablespoons softened butter and 2 ounces softened cream cheese together until light and fluffy (1-2 minutes) then add in ½ teaspoon vanilla.
Gradually mix in 2 cups powdered sugar until incorporated. Pipe into the center of each filled cookie. Add sprinkles if desired.