Recipe credit: Crazy For Crust Ingredients

For the Cakes:
1 box red velvet cake mix, plus ingredients called for to make the cake
(I used Duncan Hines and the cake mix called for 3 eggs, 1 1/4 cups water, and 1/3 cup oil.)
8 ounces cream cheese, softened
1/4 cup sour cream, room temperature
1/4 cup sugar
1 teaspoon vanilla extract
For the Frosting
4 ounces room temperature cream cheese
4 tablespoons room temperature butter
2 cups powdered sugar
2 teaspoons vanilla
2+ teaspoons heavy cream
Instructions

Preheat oven to 350 degrees. Butter and flour (or line with foil and spray wit cooking spray) two loaf pans. You can use two 9x5 loaf pans or one 9x5 and one 8 1/2 x 4 1/2.
Mix up cake mix according to package directions, using egg, water, and oil called for on the box. Divide among your loaf pans.
Beat cream cheese and sour cream in a stand mixer until smooth. You can use a hand mixer, but I find it is really hard to get all the lumps out that way! Beat in your egg, sugar, and vanilla and mix until smooth, although some lumps may remain. Evenly divide cheesecake mixture on top of each of your loaf pans. Drop spoonfuls of the cheesecake batter randomly over the top of the loaves. Using a butter knife or the back of a wooden spoon, swirl the cheesecake into the loaves. Be careful not to swirl too much or they will just blend (kind of like mine did...)
Bake for 30-35 minutes, until a toothpick inserted in the center comes out clean. Cool completely and then remove from pans.
To make the frosting: mix butter and cream cheese until smooth with a hand mixer. Mix in powdered sugar, 1 cup at a time. Add vanilla and 1 teaspoon heavy cream and mix until smooth. Add more cream, 1 teaspoon at a time, until the frosting reaches your desired spreading consistency. (I used 2 teaspoons.) Store in refrigerator.