Weigh out the ingredients
You'll need flour, brown sugar, oil, vanilla, sugar, cocoa powder, espresso powder, salt, eggs, and chocolate.
Melt chocolate & oil
In a small bowl, add the chocolate and oil. Place over a small saucepan of simmering water, and stir often until fully melted. Set aside to cool.
Meanwhile, in a large bowl, whisk in the sugars, eggs, and vanilla. Using an electric mixer, beat on high speed for about 5-6 minutes until the mixture has doubled in size.
Beat eggs & sugar
While mixing on low speed, slowly pour in the chocolate oil mixture.
Mix in melted chocolate
Once it is fully combined, add the flour, cocoa powders, espresso powder, and salt, and mix until mostly combined.
Add dry ingredients
Lastly, fold in the chopped chocolate until evenly dispersed.
Fold in the chocolate
Add the brownie batter to the prepared mini muffin tin, filling each cup about ¾ full. Bake the brownie bites for about 15-18 minutes or until a toothpick inserted comes out with a few moist crumbs. Let rest on a cooling rack and repeat with remaining batter.
Enjoy these brownie bites warm from the oven!