Greek Yogurt (Best Option)
1:1 (1 cup Greek yogurt per 1 cup sour cream)Greek yogurt has a similar fat content and acidity level to sour cream, which helps activate baking soda or powder, contributing to leavening and a tender crumb. Its creamy texture also adds moisture, preventing dryness in the chocolate cake.
For best results, use full-fat Greek yogurt to match the fat content of sour cream. Avoid overly thick varieties by stirring before measuring. The tanginess complements the chocolate flavor without overpowering it.
Compared to sour cream, Greek yogurt may impart a slightly more pronounced tang but generally results in an equally moist and tender cake with a rich flavor profile.