In a k8s cluster. How do you configure zeppelin to run spark jobs in an existing spark cluster instead of spinning up a new pod?

I've got a k8s cluster up and running in which I want to run Spark with Zeppelin.

Spark is deployed using the official bitnami/spark helm chart (v 3.0.0). I got one Master and two Worker pods running fine, everything good.

Zeppelin is deployed with the zeppelin-server.yaml from the official apache-zeppelin github.

I've build my own zeppelin container without much modification from apache/zeppelin:0.9.0..

Short pseudo Dockerfile:

FROM bitnami/spark:3.0.0 AS spark 
FROM apache/zeppelin:0.9-0 AS Zeppelin 
COPY --from spark /opt/btinami/spark/ /opt/bitnami/spark  
RUN Install kubectl 
END

I modified zeppelin-server.yaml slightly. (Image, imagePullSecret, setting spark master to the headless Service DNS of spark master)

Now I want my zeppelin jobs to run on my existing spark cluster --- with no success.

When I'm submitting zeppelin jobs (for the spark interpreter), zeppelin fires up a new spark pod and solely works with this one. Spark interpreter settings are like they should be. spark master url is set (spark://\<master-url\>:\<master-port\>), spark home as well.

While this is kind of a sweet behaviour, it's not what I want.

What I want (and what my question is) is: I want my zeppelin pod to submit the spark jobs to the existing cluster - not fire up a new pod. I am PRETTY sure that there has to be some config/env/whatever that I have to set but I simply can't find it.

So, I wanna ask: Is there anyone out there, who knows how to run zeppelin spark jobs on an existing spark cluster? I thought setting the spark master should do the job...

Kind regards Bob