E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Gooseberry Fool.
A corruption of gooseberry foulé, milled, mashed, pressed. The French have foulé de pommes; foulé de raisins; foulé de groseilles, our gooseberry fool.
1
Gooseberry fool is a compound made of gooseberries scalded and pounded with cream.