Being the exhaust in near that area and a source of heat, enough heat to 'burn' (not combust/ignite) oil; odds are it's oil leaking onto the exhaust.
The oil in the pan does not reach the level of the entry point of the dipstick tube into the engine block.
But oil splashing around could make it's way past the O-ring seal on the bottom of the dipstick tube.
If that's the area you think is the problem then I would take the dipstick tube out and inspect the O-ring for damage.
Simply remove the 1 retaining bolt on the cylinder head, twist and pull gently on the tube. It should come out relatively easy.
Do be sure first that there is no debris that will fall into the oil.
Don't "think outside the box".
There is no box.
Do it correct, or do it twice.