Preheat the oven to 350°F. Prepare an 8 x 8 square pan by buttering the bottom and sides, lining with a 9-inch wide strip of parchment paper that fits the bottom of the pan and overhangs on 2 sides.

Melt the butter and chocolate in a medium size microwavable bowl. I begin at 1 minute, remove from the microwave and stir. Continue microwaving in 30-second increments, stirring after each, until the chocolate and butter are thoroughly melted and shiny smooth.

In a separate bowl, whisk together the flour, baking powder, and salt.

To the chocolate-butter mixture, add the espresso powder and whisk until combined. Then add the sugar, eggs, and vanilla. Whisk until the mixture of smooth.

With a rubber spatula, fold the dry ingredients into the chocolate-egg mixture until well combined. Then fold in 1 cup of the pecans.

Scrape the batter into the prepared pan and smooth the top. Sprinkling the remaining 1/2 cup of pecans evenly over the top.

Bake until a skewer inserted into the brownies comes out mostly clean with a few crumbs clinging to the skewer, about 35-40 minutes.

Allow the brownies to cool completely before unmolding the brownies. Using a sharp knife, release the brownies from the two sides of the pan not lined with parchment paper. Cut into 12 bars using a serrated knife.