We recently found out that Pluto has a molten core. Since the Moon is bigger than Pluto should the Moon have had a molten core at some point in time?
About one-third of the near side of the Moon is covered by basaltic plains, called Mare. These plains are evidence that molten rock once flowed on those areas of the Moon and that in its early history the Moon experienced volcanism.
NASA analysis of Apollo era seismic data indicates the Moon has a core similar to Earth: a solid central core within a molten outer core.
The molten Lunar core is small compared to the size of the Moon and the Moon's mantle is so thick that molten rock from the core can no longer reach the surface of the Moon.
Essentially, it looks as though Pluto has a molten radioactive core and tectonic plates.
Whereas, Space.com states,
The dwarf planet probably has a rocky core surrounded by a mantle of water ice, with more exotic ices such as methane, carbon monoxide and nitrogen ice coating the surface.
These comments appear to be conjecture and are not official NASA releases based on NASA acquired data from the New Horizons probe that flew past Pluto.