Simplify the following text for a Grade 9 native English-speaking person.
Original: Yeast-raised doughnuts contain about 25 % oil by weight , whereas cake doughnuts ' oil content is around 20 % , but they have extra fat included in the batter before frying .
Simplified: Yeast-raised doughnuts contain about 25 % oil by weight , whereas cake doughnuts ' oil content is around 20 % , but they have extra fat in the batter before frying .