Preheat the oven to 350 F. Spray at least one mini bundt pan with plenty of baking spray.
Add the sugar, butter and vegetable oil to a large mixing bowl. Whisk together until smooth and creamy and slightly lightened in color.
Add in the eggs and sour cream and whisk to combine. Add in the buttermilk and whisk to incorporate.
Next, add in the flour, cocoa, vanilla pudding, baking powder, salt and baking soda and whisk just until combined.
Whisk in the white vinegar. Lastly, add in the red food coloring and whisk until all of the batter is red.
Fill each of the mini bundt pans halfway full with batter. Place into the oven to bake for 16-18 minutes or until a toothpick inserted comes out clean or with moist crumbs.
Once baked, remove from the oven and place onto a cooling rack to cool for a few minutes. If you only have one pan and are baking in batches, carefully flip the pan over onto the cooling rack. If the bundt cakes do not fall out of the pan, gently tap each one with the heavy end of a butter knife to help dislodge the cakes from the pan. Continue baking bundt cakes until all of the batter is used.
Make the Cream Cheese Frosting
After the mini bundt cakes are baked and cooled, make the cream cheese frosting. Add all of the ingredients to the bowl of a stand mixer fitted with a paddle attachment. Beat together on high speed for 2-3 minutes or until completely smooth.
Spoon into a piping bag fitted with a star tip. Pipe a small swirl of frosting onto the top of each mini bundt cake.
Storage: Bundt cakes may be stored in a baggie or airtight container in the fridge for up to 5 days.