Found this yummy recipe on a great blog. My suggestions for making it more SBD-friendly are in red brackets. Visit the website for the entire recipe.

Amazing Black Bean Brownie Recipe
From Baking With Agave Nectar: Over 100 Recipes Using Nature's Ultimate Sweetener by Ania Catalano via 101 Cookbooks Blog.
Ania's head notes encourage you to keep these brownies in the refrigerator, they will slice much better if refrigerated several hours or preferably overnight. I used instant coffee this time around, but you can find natural coffee substitute at many natural food stores.

4 ounces unsweetened chocolate
1 cup unsalted butter [Use a mix of trans-fat-free margarine and canola oil, or try using Smart Balance's 50/50 butter sticks]
2 cups soft-cooked black beans, drained well (note: canned is fine)
1 cup walnuts, chopped
1 tablespoon vanilla extract
¼ cup (granulated) natural coffee substitute (or instant coffee, for gluten-sensitive)
¼ teaspoon sea salt
4 large eggs
1½ cups light agave nectar [Depending on how many you eat in a serving and how your body reacts to agave nectar, you make want to use a mix of agave and another sugar substitute, like erythritol, stevia, or Splenda.]

Read the rest of the recipe at this link.