- In a saucepan, melt 60 ml (¼ cup) of butter. Add the flour and cook for 1 minute, stirring constantly. Add the fruit purée and bring to a boil, stirring with a whisk. Simmer gently for about 30 seconds, stirring constantly.
- Pour into a bowl, cover with plastic wrap directly on the mixture and let cool to room temperature.
- Add the sugar and the remaining butter and beat with an electric mixer for about 5 minutes or until the frosting is smooth and creamy.
This frosting will keep for about 3 days at room temperature or refrigerated. In the latter case, let cool to room temperture and beat again to restore its smoothness.