Green’s Dictionary of Slang

arrogantly, in a domineering manner.

1934		J.M. Cain Postman Always Rings Twice (1985) 56: Maybe she treat you snotty.
1934		H. Roth Call It Sleep (1977) 413: Yuh reams ’em out with dat, he says, kinda snotty like.
1942		R.L. Bellem ‘Broken melody’ in Dan Turner – Hollywood Detective Dec. 🌐 He acted snotty when I asked for Hal; so I gave him the fish-eyed focus.
1997		G. Sikes 8 Ball Chicks (1998) 217: I was talking to her real snotty like, ‘Either you do this or we’re gonna sleep on the streets’.