Depending on the context,
"turn up" means to "increase". e.g. please turn up the lights.
to "show up, appear etc". e.g. the evidence turned up by themselves; the guests failed to turn up on time.
"turn out" means "prove to be the case" The prince turned up to be a fake.
"eventuate, happen, develop, occur" Things didn't turn out to be expected.
"become clear, emerge, become apparent" It turns out that she was not at home.
"go somewhere for something" some of us turned out to vote on a rainy day.
You didn't turn out to be a good friend is CORRECT. Using turn up is WRONG. In your first example, the correct sentence should be, "if you're making a cake and you don't follow the recipe, it doesn't really turn up GOOD"