*raises hand and jumps up and down* My hair does this too! The underside is silky and 2A, sometimes even pretty much straight. The outer layer is a 2C, sometimes even bordering on 3A.

Have you tried diffusing the under layers with the pixiecurl method, maybe? It can help a bit. And so can drying your hair with your head upside-down, because the outer layers of hair aren't pressing the underlayers flatter.
Previously Joy4ever.
Changed because the "number in place of a word" thing was bugging my no-longer-14-year-old self.