This recipe comes from the book below (p.152) and Brian gives this one a 3.5 out of 5 stars.
*1/3 cup stick margarine
* 3/4 cup firmly packed light brown sugar
* 1 egg, slightly beaten (I used egg whites)
* 1 tsp. vanilla extract
* 1/2 tsp. baking powder
* 1/8 tsp. baking soda
* 1 cup all-purpose flour
* 1/4 cup mini-chocolate chips
1. Preheat the oven to 350. Spray an 8x8 (I used 9x9) baking pan with nonstick cooking spray.
2. In a medium saucepan, melt the 1/3 c. margarine.
3. Add the sugar and stir until smooth and slightly cooked, 2 minutes.
4. Blend in egg. Add the 1t. vanilla, 1/2t. baking powder, and 1/8t. baking soda; stir just to remove lumps.
5. Add the 1c. flour and stir smooth.
6. Stir in the 1/4c. chocolate chips.
7. Spread the batter in the baking pan.
8. Bake until the top is slightly set and lightly browned, 20 minutes. DO NOT over-bake.