Preheat the oven to 350 degrees F. Greased 9 by 13 by 2-inch sheet pan.
In a mixing bowl, cream the sugar and butter, beat until light and fluffy.
Add the eggs 1 at a time and mix well after each addition.
Mix cocoa and food coloring together and then add to sugar mixture; mix well. Sift together flour and salt.
Add flour mixture to the creamed mixture alternately with buttermilk. Blend in vanilla.
In a small bowl, combine baking soda and vinegar and add to mixture.
Pour batter into the prepared sheet pan.
Bake for 20 to 25 minutes or until a toothpick inserted into the center comes out clean.
Remove from heat and cool completely. When the cake is cooled, cut into 1-inch cubes.
Place cubes onto 11 by 17-inch cookie sheet.
Place in oven for 10 minutes.
Combine the half-and-half, eggs, egg yolk, salt, and vanilla in a medium bowl. With an electric hand mixer in a large bowl, beat the cream cheese and sugar until smooth.
Mix in the half-and-half mixture.
Place the red velvet cubes in a large baking dish or 8 individual ramekins.
Add the pudding mixture to the dish. Make sure the cake cubes are completely covered.
Bake for about 30 minutes, or until the pudding is set.