  We use N-body simulations to examine the effects of mass outflows on the
density profiles of cold dark matter (CDM) halos surrounding dwarf galaxies. In
particular, we investigate the consequences of supernova-driven winds that
expel a large fraction of the baryonic component from a dwarf galaxy disk after
a vigorous episode of star formation. We show that this sudden loss of mass
leads to the formation of a core in the dark matter density profile, although
the original halo is modeled by a coreless (Hernquist) profile. The core radius
thus created is a sensitive function of the mass and radius of the baryonic
disk being blown up. The loss of a disk with mass and size consistent with
primordial nucleosynthesis constraints and angular momentum considerations
imprints a core radius which is only a small fraction of the original
scale-length of the halo. These small perturbations are, however, enough to
reconcile the rotation curves of dwarf irregulars with the density profiles of
haloes formed in the standard CDM scenario.
