Quadruple Chocolate Brownies - cooking recipe

Ingredients

1 1/4 lbs unsalted butter, softened
1 lb unsweetened chocolate, chopped
5 1/2 cups sugar
16 large eggs
2 tablespoons pure vanilla extract
1 1/2 teaspoons kosher salt
3 3/4 cups all-purpose flour
1/2 lb bittersweet chocolate, chopped into 1/2-inch pieces
1/2 lb white chocolate, chopped into 1/2-inch pieces
1/2 lb milk chocolate, chopped into 1/2-inch pieces
parchment paper

Preparation

Preheat oven to 300*F.
Line bottoms of two 9x13-inch baking pans with parchment paper.
In a large saucepan, melt the butter with the unsweetened chocolate over low-heat, stirring frequently, until melted.
In a large bowl, whisk the sugar with the eggs, vanilla, and salt.
Add the melted chocolate and whisk until smooth.
Add the flour and whisk until incorporated.
Stir in 5 ounces of each of the chopped chocolates.
Spread the batter into prepared pans.
Place the remaining chopped chocolates seperately into 3 small microwave safe bowls and melt.
Using a spoon, drizzle the melted chocolate over the batter.
Using a table knife, make swirls in the batter for a marbled effect.
Bake for about 35 minutes, rotating the pans about halfway through, until the tops are shiny and the brownies are set.
Transfer the brownies to a wire rack to cool completely before cutting into squares.