This is a beloved recipe from two wonderful ladies in Maui (Makawao!) who used to make and sell this. We would have it shipped to us, until they told us that they had stopped making it. Fortunately, they gave us the hint of adapting a well-known lemon curd recipe for passionfruit, and voila, lilikoi butter! Finding fresh passionfruit is almost impossible outside of Maui, and cheap Goya brand purees lack flavor, but fortunately a few restaurant supply companies sell it (Perfect Puree of Napa Valley - to buy individually you have to go in person!).
1/2 cup passionfruit puree
1/2 cup sugar
6 tbsp butter cut into chunks
Whisk eggs, then whisk in passionfruit and sugar. Add butter. Whisk over low heat, scraping sides and corners of pot until butter thickens and simmering slightly. Whisk constantly, or eggs will start to cook! Remove from stovetop and scrape through a fine strainer a few times. Refrigerate and use within a week.