From America's Test Kitchen Season 5: Bake Sale Favorites
Blondies are first cousins to both brownies and chocolate chip cookies. Although blondies are baked in a pan like brownies, the flavorings are similar to those in chocolate chip cookies—vanilla, butter, and brown sugar. They’re sometimes laced with nuts and chocolate chips or butterscotch chips. But even with these extras, blondies can be pretty bland, floury, and dry. We set out to fix the blondie so it would be chewy but not dense, sweet but not cloying, and loaded with nuts and chocolate.
We found that the key to chewy blondies was using melted, not creamed, butter because the creaming process incorporates too much air into the batter. For sweetening, light brown sugar lent the right amount of earthy, molasses flavor. And combined with a substantial amount of vanilla extract and salt (to sharpen the sweetness), the light brown sugar developed a rich butterscotch flavor. To add both texture and flavor to the cookies, we included chocolate chips and pecans. We also tried butterscotch chips, but we found that they did little for this recipe. On a whim, we included white chocolate chips with the semisweet chips, and we were surprised that they produced the best blondie yet.
Makes 36 bars
Despite their name, Congo bars have nothing at all to do with Africa. In fact, they are little more than blondies enriched with coconut -- an ingredient that was exotic in years past perhaps but is far from it these days. We tried adding both sweetened, flaked coconut and unsweetened, shredded coconut to our blondies, and tasters unanimously preferred the unsweetened. Sweetened coconut did little but make the bars overly sweet and unpleasantly chewy. We were able to extract a bit more flavor from the unsweetened coconut by toasting it golden brown before adding it to the blondie dough. If you have trouble locating unsweetened shredded coconut, try a natural food store or an Asian market. Keep a close eye on the coconut when toasting as it can burn quickly.