Preheat the oven to 350 degrees Fahrenheit. You will be using a bundt pan but will want to grease it just before pouring the cake into it so do not prepare it yet.

In a medium sized mixing bowl use a hand or stand mixer on low to beat together the pound cake mix, pudding mix, eggs, half and half and melted butter just until combined, about 30 seconds.

Beat the mixture for an additional 1-2 minutes or until it is a thick, light batter.
Remove ½ cup of the batter and place it into a small mixing bowl and add red food coloring. Mix well until you have the shade of red you desire.

Remove another ⅓ cup batter and do the same with the yellow food coloring.

Remove ⅓ cup of batter, place in a small bowl and add the green coloring.

Finally, remove one last ⅓ cup and add the purple coloring.

Spray the bundt pan well with cooking oil and then scoop ¾ of the plain cake batter into the pan and gently even it out with a spatula or spoon.

Place the red batter into a piping bag or disposable sandwich bag and cut off a small amount of the tip.

Pipe the red batter in a circle in the center of the bundt pan. Use a spoon to gently spread it out, leaving an edge of about ½ an inch, between the red batter and the edge of the pan.

Repeat the process with the yellow batter, using a spoon to spread it out but leaving a thin edge of the red showing.

Repeat again with the green and then the purple batter. You should be able to see a little of every color and all of the purple batter.

Gently scoop the remaining plain batter onto the top of the colored batter, or use another piping bag to pipe it on and spread it into an even layer with a spoon.

Bake for 50-60 minutes or until a toothpick comes out clean.

Allow the cake to cool for 10 minutes and then turn it out, gently, onto a cake platter or serving plate.

After the cake has cooled completely, about 45 minutes, mix together the frosting and half and half until you have a thick pourable glaze.

Gently pour the glaze over the top center of the cooled cake and allow it to slowly drip down the cake.

Serve garnished with rainbow sprinkles, optional.