I used this recipe that cailin_t posted a while ago and heartttcore helped me dig up in the memories. I'll repost it with my modifications:
3/4 c sugar
3/4 c flour
1/2 c chopped walnuts (optional)
1/4 c cocoa
1 tsp. baking powder
1/4 tsp. salt
(I also put in a few handfuls of vegan chocolate chips)
1/4 c vegetable oil
1 tsp. vanilla extract
Stir with a fork until just blended. You might have to add a little water in as you stir to compensate for the fact tha the icecream is thicker than water or soymilk. Pour into greased 9-inch square pan. Bake at 350 degrees for 22-25 minutes.
These are perfect :) Yummy, fudgey, heavenly brownies, and the icecream just made them richer! Triple chocolatey goodness!