Directions

1. Gather all ingredients. Preheat the oven to 350 degrees F (175 degrees C). Lightly coat a 9x13-inch baking pan with baking spray; set aside.
2. Whisk together cake mix, buttermilk, oil, eggs, and food coloring in a medium bowl until fully combined and no dry streaks remain. Transfer to the prepared baking pan and spread in an even layer.
3. Bake in the preheated oven until a wooden pick inserted in center comes out clean, 20 to 25 minutes. Let cool completely in pan on a wire rack, about 1 hour.
4. Beat cream cheese and butter with an electric mixer on medium speed until light and fluffy, 1 to 2 minutes.
5. Gradually beat in powdered sugar with mixer on low speed, until smooth and fully combined, stopping to scrape down sides of bowl as needed, about 3 minutes. Add vanilla and salt and beat until just combined.
6. Using an offset spatula, spread cream cheese frosting evenly over the top of the cooled cake. Garnish with sprinkles, if desired.