The use of a controlled, removable angular dispersion applied to the signal beam in a plane orthogonal to that containing the noncollinear angle is experimentally demonstrated as a technique to broaden the gain bandwidth in optical parametric chirped-pulse amplification. With a pump beam centered at 526 nm the supercontinuum signal is amplified in the 900 to 1220 nm range in a beta-barium borate crystal with a gain >1000. This represents a bandwidth improvement greater than 30% relative to conventional designs.