Dank daddy deep dish can apply to many things but it is reserved for the dankest, deepest, daddy shit.
Dank daddy deep dish (ex: "that good good kush") is any good shit that a dank daddy dished you. A dank daddy being a dealer of that good shit.
"Does Danny got that good shit?"
"Yeah, Danny's a total dank daddy dealer. He deals the dankest dank daddy deep dish."