1. Warm milk until warm but not boiling. Add yeast and let set until proofed.
2. Mix sugar with butter and cream cheese until smooth, then add eggs one at a time. Mix until combined. Add flour and salt, then the yeast mixture. Mix until elastic and smooth.
3. Cover the bowl and allow the dough to rise in the fridge for two hours or up to overnight.
4. Remove the dough from the fridge and roll into balls, 1/2-inch (one centimeter) thick. Let rise at room temperature until doubled in size, about one hour.
5. Heat a pan with oil until it reaches 350 degrees Fahrenheit (175 degrees Celsius). Fry doughnuts in batches until browned.