Burning oil smell inside and out

I have begun to notice an occasional burning oil smell in my 2011 Cruze 1LT since its last oil change at the dealer. This has been on and off since then, about 2 months. Checked the oil level seems good. However, I did notice that they seem to have spilled a fair bit around the fill cap on the top of the engine. Not a big deal and I figured that would burn off pretty quick and it wouldn't smell after that. But every once and a while it still does. For what it's worth it seems to be more prevalent after I stop on a downhill incline. Is there a chance oil's like sloshing out somewhere onto something hot?

Anything else I should be checking? What's a good way to clean up the oil?