2sticks (1 cup) unsalted butter
2cups all-purpose flour
1heaping teaspoon kosher salt
4teaspoons good-quality vanilla extract
1 3/4cups dark brown sugar
1cup bittersweet chocolate chips
Melt the butter in a medium-sized saucepan. Swirl it around a few times. It will foam and spatter. After 3 to 4 minutes, it will start to smell nutty. Don’t walk away. It’s ready when the sizzling quiets down and you see little brown bits drop to the bottom of the pan. Pour into a large bowl. Cool completely (about 30 minutes). Alternatively, if you want a blondie marbled with chocolate, cool butter for only 5 minutes and proceed with the recipe. The warm dough will melt the chocolate chips a bit.
Heat oven to 350° F. Prepare your 8 by 8-inch baking pan with butter and flour, parchment paper, or aluminum foil. Set aside.
Whisk together flour and salt. In another bowl, whisk together eggs and vanilla. Set aside.
Add brown sugar to the cooled butter. Mix with a wooden spoon for about a minute.
Add egg/vanilla mixture to butter/sugar mixture. Mix until combined and shiny, about 20 seconds.
Add flour mixture to the butter/sugar/egg mixture. Mix until there are still a few pockets of flour visible. Add chocolate chips. Mix until evenly distributed and all flour pockets are gone, but be careful not to over-mix! Spoon dough into your prepared baking pan. Spread evenly with the back of your wooden spoon (it will keep its shape). Bake for 25 to 30 minutes. You can’t do the toothpick test with this because it always comes out clean. Instead, look for a crispy top that's just starting to crack.
Remove from the oven. Cool completely before removing from the pan. The blondie block should pop right out (either pull out by parchment/alumninum foil or if in a greased pan, just invert onto a cutting board and carefully flip it back over). Cut into desired portion sizes. These keep for a few days at room temperature in an airtight container. Or you can freeze them for a few months.