I think under Lemonade you can do that, especially with AMD systems, using the models that allow for hybrid operation. Prefill happens on the NPU and token generation happens on the GPU. Not sure if this is faster or better than just doing it all on the GPU side.
It's slower but more power efficient. I think only some form of onyx models are available and I couldnt get anything to run on the first gen NPU's in the 7940HS cpu.
FastFlowLM is what you're looking for - Lemonade does package it, as sibling comment says.