In a large bowl, combine butter with powdered sugar and vanilla extract until combined. Form the mixture into oval shapes and set onto a plate. Freeze for at least 20 minutes.
Place the chocolate chips into a microwave-safe bowl, and melt in the microwave in 30-second intervals, stirring well until it is fully melted and smooth.
Coat each buttercream truffle in the chocolate and set onto a plate. Let sit until it is completely set.