Could you substitute pecans for walnuts in this recipe? The friend I’d make this for loathes walnuts but loves pecans.

I bet that would be delicious! (My mom prefers pecans to walnuts too, so I'll have give this a try myself.)

Yes, you certainly can. Pecans would be delicious in these flourless (not walnut) brownies.

Someone I bake for on a regular basis greatly prefers pecans over any kind of nut, so if I ever make these, I'll be using pecans, too! ;o)