Supports for dense Voronoi pieces
One feature of Cura is the ability to set supports to build plate only. This would remove any supports internal to the model, as your model has a base that is not considered the build plate or raft. In the image provided, you would have some complications, I believe, as there would be no supports on the outside of the model if it was directly over the base.



As you are not eliminating other options, you can also turn off supports in Cura, load your model into Meshmixer and make use of their support feature, which allows you to adjust placement, size and other parameters in order to get a good result.

The flexibility is limited only by your imagination: