Beat butter and cream cheese at medium speed with an electric mixer until creamy. Gradually add powdered sugar, beating at low speed until blended. Increase speed to medium, and slowly add coconut milk and vanilla, beating until smooth.
This is a keeper. I substituted coconut extract for the vanilla extract. You can find the cream of coconut in the alcohol section of your grocery store. They use it to make piña colada's. Totally different than coconut milk.