01 -
Preheat oven to 350°F (175°C). Line a 9x9-inch baking pan with parchment paper, spray lightly with non-stick baking spray
02 -
In a large bowl, sift together flour, baking powder, salt, cocoa powder, and espresso powder. Set aside
03 -
In a medium saucepan, combine butter, oil, and 1/3 cup of sugar. Heat over medium heat, stirring frequently, until butter is completely melted
04 -
In a large mixing bowl, whisk together eggs, egg yolk, vanilla, and remaining sugar until well combined, about 30 seconds
05 -
Slowly pour warm butter mixture into egg mixture, adding gradually and whisking constantly until completely combined
06 -
Add dry ingredients and chocolate chips to wet mixture. Using a rubber spatula, gently stir until just combined. Do not over mix
07 -
Scrape batter into prepared pan and smooth the top. Bake for 28-30 minutes, until edges are firm and top is shiny and slightly cracked
08 -
Place pan on a cooling rack and cool completely before slicing