How to Make the Perfect Blondie

That's too bad, because those times I've run across a blondie that's moist, chewy, slightly dense, and full of complex butterscotch goodness, I've always thought that it could hold its own next to any baked treat, let alone a brownie. I wanted to perfect this bar and give it the respect it deserves.

Before I got down to serious testing, I decided to experiment with two popular notions—that blondies are simply brownies stripped of chocolate, or they're chocolate chip cookies pressed and baked in a pan. (There's actually an argument for the first idea; see “Move Over, Brownie—Blondie Got Here First.”)

I took recipes for chewy brownies and chewy chocolate chip cookies, eliminated the chocolate in the former, and patted the dough for the latter into a 13 by 9-inch pan. Not surprisingly, when I baked them both off, each confection was a dud.

Without the starch contributed by the cocoa powder in the brownie recipe to help absorb moisture and fat, the bars were gummy and greasy. They were also sickeningly sweet. As for the chocolate chip cookie bars, which I baked long enough to ensure that the dough at the center of the pan wasn't gooey, they were mostly dry and tough, particularly the edge pieces. They also lacked some of the nice toffee notes that cookies gain from browning when they are baked individually on a cookie sheet.

Clearly, a blondie has its own identity, and I'd have to treat it that way to create a successful version.

The first decision I faced was the mixing method. Blondie recipes typically call either for creaming butter and sugar and then adding the eggs and dry ingredients or for mixing melted butter with the sugar and eggs before incorporating the dry ingredients. Since creaming the butter and sugar incorporates air that results in a cakey texture, I settled on the second method, which leads to a denser, chewier bar.

Next order of business: boosting butterscotch flavor. Most blondie recipes call for light brown sugar, and I wondered if using dark brown sugar instead would help just a little. Working with a standard recipe from my research—a 1:1 ratio of sugar to flour, salt, baking powder, a couple of eggs, vanilla extract, and one stick of melted butter—I ran a quick side-by-side test. Interestingly, most tasters panned the dark brown sugar for making the blondies taste more like molasses than butterscotch; they also preferred the more golden color of the bars made with light brown sugar.

But I did have something more promising in mind to try: Instead of just melting the butter, I would brown it to create warm, toasty, nutty flavors. So for my next batch of bars, I cooked the butter in a skillet until the milk solids had turned a dark golden brown and had a nutty fragrance, combined it with the other ingredients, and then baked the batter in a 13 by 9-inch pan in a 350-degree oven until lightly golden. This was a big step in the right direction: The blondies tasted decidedly more nutty and rich.

A colleague had another idea: Since vanilla extract's earthy, woodsy notes mirror and complement butterscotch flavors, why not try more of it? Doubling the amount of vanilla worked so well to deepen the warm caramel flavor in the bars that I kept going and tripled it.

Increasing the vanilla gave me the idea to increase another ingredient: the salt. Salt is included in most sweet applications because it helps sharpen all the flavors, particularly nutty, buttery ones. When I doubled it from ½ teaspoon to 1 teaspoon, those flavors stood out a little more in my blondies and the sweetness a little less.

But I still wanted to cut back more on the sweetness. When I decreased the sugar, the results were a good reminder that sugar is never merely a sweetener in baking; it plays multiple roles—and messing with its proportions has consequences. Because brown sugar adds moisture and, like all sugar, is hygroscopic (it attracts and retains moisture), even ¼ cup less made the bars drier. Sugar also acts as a tenderizer by interfering with the flour proteins' ability to form gluten, and less of it made the bars a little tough.

I needed a sweetener that performed all the positive actions of sugar but wasn't too sweet. The obvious choice was corn syrup. Unlike the high-fructose corn syrup used to make soda, which is much sweeter than sugar, regular corn syrup is actually less sweet: Made by breaking down starch into glucose molecules and small glucose chains, corn syrup is about 50 percent less sweet than white and brown sugars. I subbed in ⅓ cup for ¼ cup of brown sugar. Even though the corn syrup's volume was greater, the cookies tasted noticeably less sweet.

I had the flavor right where I wanted it, but I wasn't quite done. Some tasters thought the blondies lacked stature. When I scaled up my recipe by 25 percent to create thicker bars, I found I had to double the baking time. This had the unintended but happy consequence of drying out the top of the batter, so it browned more deeply and had even more nutty, caramelized flavor while the interior remained moist and chewy.

It was time to add complementary elements such as nuts and chips. Most recipes call for walnuts, but I chose pecans, which have a more buttery flavor. For chips, I passed on white chocolate and butterscotch morsels as well as dark chocolate chips. Instead I opted for milk chocolate morsels, whose mild dairy sweetness didn't overpower the caramel flavor.

As a final touch, I crumbled flaky sea salt over the batter before it went into the oven. After the bars cooled completely, I cut them into squares. These blondies were exactly as I'd envisioned: moist, chewy, wonderfully complex and butterscotchy, and not too sweet. The nuts and chocolate played nicely with the browned butter, and the crunchy pops of flaky salt made for an appealing contrast.

I was equally thrilled to find that the bars kept very well—for close to a week—at room temperature. Though I doubted they'd last that long.