• Preheat oven to 350°F/175°C. Prepare a large bundt pan with shortening, then dust with flour.
• In a stand mixer, or using a hand mixer and a large mixing bowl, add the cake mixes, eggs, water, and oil. Mix for 2-3 minutes.
• Divide the batter into 4 or 5 bowls (depending on how many colors you’ve chosen). Add food coloring to each bowl, leaving one without color.
• Pour batter into the prepared Bundt pan, one color at a time. You may have more cake batter than you need. Only fill the pan ⅔ fill, or it will overflow. Bake the cake for 50 - 60 minutes, or until done.
• Let the cake cool for 10 minutes in the pan. Then loosen the edges of the cake and turn it out onto a wire rack to cool completely.

To Make the Glaze:

• Add powdered sugar, vanilla, and milk to a bowl. Using a whisk, mix together slowly, adding more milk one tablespoon at a time until the glaze is your desired consistency.
• Place the cooled cake on a plate. Pour the glaze slowly over the cooled cake. Add sprinkles before the glaze sets.