01 - Preheat your oven to 350°F. Line a 9x13-inch baking pan with parchment paper, ensuring an overhang on the sides for easy removal of the brownies later.
02 - In a microwave-safe bowl, combine the unsalted butter and chopped bittersweet chocolate. Melt in 30-second intervals, stirring after each, until completely smooth. Allow the mixture to cool slightly.
03 - Whisk the granulated sugar and light brown sugar into the slightly cooled chocolate mixture until thoroughly combined.
04 - Add the large eggs one at a time, whisking vigorously after each addition to ensure full incorporation. Stir in the vanilla extract.
05 - Gently fold in the all-purpose flour and salt just until no dry streaks remain. Be careful not to overmix the batter.
06 - Pour the prepared brownie batter into the lined baking pan and spread evenly. Bake for 25 to 28 minutes, or until a wooden skewer inserted into the center comes out with moist crumbs. Let the brownies cool completely in the pan before proceeding.
07 - For the praline topping, melt the 1/2 cup of unsalted butter in a medium saucepan over medium heat. Stir in the 1 cup of light brown sugar and heavy cream. Bring the mixture to a gentle boil and simmer for 2 to 3 minutes, stirring constantly.
08 - Remove the saucepan from the heat. Whisk in the sifted powdered sugar, vanilla extract, and a pinch of salt until the mixture is smooth. Gently fold in the toasted chopped pecans.
09 - Pour the warm praline topping evenly over the completely cooled brownies, spreading it from edge to edge. Allow the topping to set at room temperature for 30 to 40 minutes, or until it has firmed up.
10 - Using the parchment paper overhang, carefully lift the cooled brownies from the pan. Cut them into individual squares and serve.