Sapling Tree Generator - Thick trunk with base splitting?

I’m looking to create a tree like this:

That is, with big trunk and multiple base splits.
I tried looking at tutorials and playing with the sapling tree generator plugin, but I can’t seem to get the result.

For the thick trunk, I couldn’t find any setting that would allow me to change the width of the trunk. How can I do that? what am I missing?

For the base splitting, I tried adding splits at the 1st level, but it seems to just create splits up until the top and I’m not sure how to change it so that branches would start from the top of the split.