You can bake with unripe pears.
Unripe pears are actually great for baking with because the unripe pears don't fall apart as easily and hold their shape better than ripe pears.
Ripe pears can fall apart when used in baking foods and they don't hold their shape as good as unripe pears although you can still use ripe pears to bake with.
But I find that baking with unripe pears makes the baked goods turn out much better.
You can also puree the unripe pears and make baby food out of them.
Although the riper the pear the better it will taste.
But it's okay to eat or cook or bake with unripe pears.
I prefer to eat ripe pears when I want to eat the pears uncooked but I bake a lot of baked goods with unripe pears and the baked goods turn out just fine.