Nutritional Info:Makes about small 30 pieces,and below is calorie for 1 piece 

Calories
180
Total Fat
10.1g
Sat. Fat
5.9g
Cholest.
43.8mg
Sodium
13.3mg
Carb.
23.2g
Fiber
0.9g
Sugars
18.4g
Protein
2.1g

Ingredients:

  1. 3/4 pound (12 ounces) (340 grams) semi sweet chocolate, coarsely chopped (can also use 2 cups semisweet chocolate chips)
  2. 1/2 cup (113 grams) unsalted butter, cut into pieces
  3. 3 large eggs, at room temperature
  4. 1 cup (200 grams) granulated white sugar
  5. 1 teaspoon (5 grams) vanilla extract
  6. 3/4 cup (95 grams) all-purpose flour
  7. 1/2 teaspoon (1 gram)baking powder
  8. 1/4 teaspoon salt


Method:

Preheat your oven to 350 degrees F (180 degrees C). Butter (or spray with a nonstick cooking spray) an 8 inch square (20 cm) baking pan. 
Then line the bottom of the pan with parchment paper.
Melt the chocolate and butter in a large heatproof bowl placed over a saucepan of simmering water. This is called double boiler method,using the steam heat from water we can melt the chocolate chips .

Remove from heat and set aside to cool to room temperature. 
Meanwhile, in a large bowl whisk (can use a hand mixer) the eggs, sugar, and vanilla extract until frothy. 
Fold in the melted chocolate mixture.
Whisk together the flour, baking powder, and salt and then fold into the chocolate mixture until combined.
Pour into your pan

 and bake for about 30minutes, or until a toothpick inserted in the center comes out with lots of moist crumbs and the brownies are just starting to pull away from the sides of the pan. You will notice that the top of the brownies will be dry and slightly cracked.
 Remove from oven and let cool on a wire rack for a few hours so the brownies have time to become firm enough to cut. 
Invert it into a plate by loosening the edge,remove the parchment paper and cut into pieces.Makes about 30 small pieces or 16 medium squares.
Serve at room temperature or chilled. These brownies can be frozen.