Recipe lightly adapted from and with thanks to Tori Varey
2cupsheavy whipping cream
Melt the butter in a small saucepan over medium heat. Add the cream and whisk to combine. In a small bowl, whisk or stir together the sugar and flour. Add the flour and sugar to the saucepan along with the egg, nutmeg, and salt. Whisk continuously for 10 minutes, until the sauce thickens enough to coat a spoon. Remove from the heat and stir in the Kahlua and vanilla. Serve warm over the dessert of your choice. Enjoy!
If you prefer not to use Kahlua, you can skip it and add an additional teaspoon of vanilla to the sauce. I've made this sauce with and without the Kahlua and it's excellent both ways.