Coconut Rum Sauce

Ingredients

1/2 pound (2 sticks) unsalted butter, melted
2/3 cup heavy cream
2/3 cup unsweetened coconut milk
1 cup granulated sugar
1/3 cup packed light brown sugar
1 large egg yolk, beaten
1 cup dark rum

Instructions

Combine all the ingredients except the rum in a small saucepan and cook over medium-low heat, whisking constantly, until the sauce has thickened and coats the back of a spoon, about 10 minutes. Do not allow the sauce to boil or the egg will curdle and the sauce will not be smooth. (If this does happen, then simply strain through a fine-mesh sieve.) Remove from the heat, stir in the rum, and set aside to cool slightly.

Makes about 2 cups