Bernhart, the flower and more particularly the plant shows a heavy influence of P.Paeony 'Regency'. I would suggest that it could be a direct Paeony 'Regency' cross or a P. Amanda crossing. The other parent would be another of the same color lines. Is it a seedling or division of a plant you have purchased????
If its a division, its probably a hybrid from a Ratcliffe cross from a few years back or similar breeding from here in Australia.