Oil instead of butter = long-lasting moisture
Yogurt = tender crumb
Low baking temperature = even softness
Room-temperature ingredients Optional Softness Boost (Highly Recommended)
Brush warm cake with:
¼ cup warm milk + 1 tsp sugar + a few drops vanilla
This makes it bakery-level soft.
Variations
Chocolate: replace ¼ cup flour with cocoa powder
Lemon: add zest + 2 tbsp lemon juice
Orange: replace milk with fresh orange juice
Result
A cake so soft it springs back when touched — perfect plain, frosted, or layered.