You can use Boolean Union to combine the handle and the bowl.

First get the handle to be a solid with planar ends:


Then select the handle solid but for the bowl only select these 2 faces:


Then you can use Construct > Boolean > Union and it will only cut the handle with those selected faces on the bowl and not the inner face of the bowl. That's called a "subset boolean".

The result will then be a combined solid and can then be processed by the printer's slicing software.


- Michael