Perhaps your new favorite bean dish:
1. whipping cream with milk, sugar and coffee beans, infuse for half an hour.
2. pour cream mixture through a sieve into a whipping kettle to the egg yolk and stir. Heat in a hot water bath, stirring with a rubber spatula, for 8-10 minutes until sauce is thickened and creamy.
Cool the sauce, season with coffee syrup and serve with the muffins.