PWNED

Hello! I need to print the model on the attached photo but I have a problem: I want to fill the hole with a flat layer because I'm gonna glue this piece to another one and I need to maximize the available surface in order for them to stick together. Is there any option available on Cura to do so? Keep in mind I can change the orientation of the model: the hole is supposed to be on top, so I was wondering if there is a "fill top layer" option or something like that. Hope someone can help!