We can build simple simulated universes. None powerful enough to include an intelligence, but we can build simple ones.
In those simple universes, we can build simulations of other simple universes.
For a concrete example, we have built computers, in in those computers we have built minecraft, and inside minecraft we have built a computer capable of running programs.
Now, in our universe, complexity (information processing) has a cost. As does it in universes we create.
It seems reasonable that we could come up with theoretical limits on the ratio between the complexity of the simulating universe and the simulated one.
We can then determine if our universe is complex enough to host a sufficiently complex universe that could itself host a simulated universe, both of which contain intelligences. I will call this "not at the end of the chain".
If we are "at the end of the chain", and our universe is insufficiently "rich" to simulate a universe containing intelligence that itself could then host a universe containing intelligence, that is evidence we are not simulated.
If we are not "at the end of the chain", then that is evidence we are simulated.
This is because the very existence of that chain implies where we are on that chain is a matter of "luck" -- we could very well be on rungs even lower.
However, the intelligence at the very bottom of the chain, which doesn't have further links under it, is an unlikely intelligence to be in the event there is such a chain. It is less plausible that we are in that special location, than if we are just another link, basically.
On the other hand, I could see the argument that when simulating a universe containing intelligence, the interesting part is that universe not the universes it simulates. So making universes that are just barely able to support intelligence in your simulation might be optimal from a simulators perspective.
The ratio still seems interesting towards this question. If simulated universes can be almost as rich as the one simulating them (ie, the overhead of simulation is cheap), it pushes forward a seeming certainty that we are a simulated universe. If the overhead is large, that leaves a huge conceptual space where an intelligence could exist, but no simulation could.