Preheat your oven to 180°C (350°F). Line your 9x9-inch baking pan with parchment paper, leaving some overhang for easy removal later.
In a medium mixing bowl, combine the chopped dark chocolate and unsalted butter. Microwave in 20-second intervals, stirring in between, until the mixture is completely melted and smooth.
Once melted, stir in the ground espresso coffee until well incorporated.
Add the caster sugar, organic maple syrup, and vanilla extract to the chocolate mixture. Whisk until combined and smooth.
Crack in the large free-range eggs, one at a time, whisking well after each addition.
In a separate bowl, whisk together the all-purpose flour, Dutch-processed cocoa powder, and a pinch of sea salt flakes. Gradually fold the dry ingredients into the wet mixture using a spatula, being careful not to over-mix.
Pour the brownie batter into the prepared baking pan, spreading it evenly. Bake for 25-30 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs.
Allow the brownies to cool in the pan for about 10 minutes before lifting them out using the parchment paper. Let them cool completely on a wire rack before slicing into squares.
