2 sticks unsalted butter (plus more for greasing the pan)

1 pound (2 cups firmly packed) light brown sugar

2 teaspoons baking powder

1/4 teaspoon salt

1 teaspoon pure vanilla extract

2 cups all-purpose flour (see Cook's note)

2 large eggs

1 cup semisweet chocolate chips

1 cup chopped pecans, optional

Cook's note: To get the proper texture, do not use an electric mixer. You do not need to sift the flour, but spoon the flour into the measuring cup so as not to pack it down too much. Use the spoon handle to brush away extra flour and thereby "level" the top of the measuring cup.

Preheat the oven to 350 degrees. Grease a 9-inch-by-12-inch baking pan well with butter. Set the pan aside.

Melt the 2 sticks of butter in a 2-quart microwave-safe bowl covered with a paper towel. Remove the bowl from the microwave, and add the brown sugar. Stir well. Add the baking powder, salt and vanilla extract, stirring until completely incorporated. Stir in the flour, again stirring until it is well mixed. The batter will be very stiff.

Crack the eggs into a small bowl, and beat them well with a fork or whisk. Add the eggs to the batter and stir with a spoon until they are completely incorporated. Stir in the chocolate chips (and the nuts, if using).

Spread the batter in the greased pan. The batter will be stiff and sticky. You may have to spread it to the edges of the pan with the back of a spoon, but don't worry too much about getting it exactly even, as the batter will spread as it bakes.

Bake until the top begins to get golden brown and the blondies just begin to pull away from the sides of the pan, about 20 to 25 minutes. (Baking time will vary depending on your oven and the type of pan.) Do not overbake! Cool for at least 20 minutes, and cut into small squares. Store in an airtight container or cover well with plastic wrap. These bars freeze very well and improve in flavor after the first day.

Makes 2 dozen

Approximate values per blondie: 216 calories (41 percent from fat), 10 g fat (6 g saturated), 38 mg cholesterol, 2 g protein, 31 g carbohydrates, 1 g dietary fiber, 59 mg sodium