Preheat oven to 325 F and position oven rack in the middle.
Prepare an 8”x8” brownie pan by spraying with baking spray and lining the bottom and sides with baking paper.
Whisk together flour, baking powder, and salt in a small bowl, set aside.
Place butter, milk chocolate, and cocoa powder in a bowl and place over a saucepan of simmering water to melt together.
Stir occasionally with a spatula, making sure the water in the saucepan doesn’t run out, till everything is blended. Pull off saucepan and set aside to cool.
Using a stand mixer fitted with the whisk attachment, whisk eggs, sugar, and vanilla extract for several minutes until the mixture is light and fluffy.
Pull the bowl off the mixer and gently fold in the cooled chocolate mixture, folding with a spatula until nearly completely mixed.
Sift the dry ingredients over the chocolate mixture, folding with a spatula until combined.
Fold in dark chocolate chips and pecans.
Bake for 25-30 minutes until a skewer inserted in the center comes out clean.