Maybe you could advance all your pawns and do the same thing?
Something to protect your trapped knight seem necessary. Maybe move b2-b3 or c3-c4?
My engine says that white is a little better after 1. c4 Nf6 2. Bd2 0-0 3. Nc3 e5 4. d5 Nb4 5. Bb1 a5 6. a3 Na6 7. Na4 e4 8. Nd4 Bg4 9. Qc2