1. Place the butter and oil in the bowl fitted with the mixer. Mix at speed 3 at 160°F for 3 minutes.
2. Add chocolate and mix at speed 3 at 110°F for 5-6 minutes or until chocolate is melted.
3. Replace the mixer with the kneading/crushing blade. Add the condensed milk and vanilla. Mix at speed 12 for 30 seconds.
4. Place the mixture in a dish and refrigerate until ready to use.