Well, I stumbled upon an interesting little post today. Here's the bulk of it:
Researchers used pureed cooked cannelli beans to replace 25%, 50%, and 75% of the shortening in a brownie recipe. They also baked brownies without any beans. The resulting goodies were rated for looks, color, tenderness, texture, flavor, and overall acceptability by 120 untrained student, faculty, and staff volunteers. The 25% and 50% bean brownies were rated about the same overall as the 0% bean brownies (75% bean brownies were not as well received).