Preheat oven to 160C.
Melt butter in saucepan over med heat.
Continue to cook butter until brown and butter emits a nutty aroma.
Remove from heat and stir in sugar.
Whisk in cocoa powder, salt, espresso powder, and baking powder.
Allow mixture to cool for 5 minutes while you line your 8x8 inch baking pan with parchment paper, and lightly grease it.
Mix in egg one at a time.
Until batter is smooth and well combined.
Mix in flour and vanilla essence.
Beat until batter is thick, shiny, and no streak of flour can be seen.
Fold in chocolate chips.
Pour batter into prepared pan, and top mini chocolate chips on top.
Bake for 25 minutes, until skewer inserted comes out almost clean.
Cool brownie in pan on wire rack completely before cutting into portions.