Instructions

• Preheat the oven to 350°F (175°C). Line an 8"×8" baking pan with parchment paper, leaving some overhang for easy removal.
• In a medium bowl, whisk together the flour (or the buckwheat flour alternative), Dutch-process cocoa powder, salt, and baking powder. Set the dry mixture aside.
• In a medium saucepan over medium-low heat, combine the 1/4 cup unsalted butter and 1 cup semi-sweet chocolate chips (the amount designated for the brownie base). Stir frequently until the butter and chocolate are fully melted and smooth. Remove the saucepan from the heat.
• Off the heat, add the 1 cup granulated sugar, 1/2 cup Irish cream, and 1 teaspoon vanilla extract to the melted chocolate mixture. Stir until combined.
• Add the large egg to the chocolate mixture and stir just until incorporated. Do not overmix.
• Fold the reserved dry ingredient mixture into the chocolate batter just until no streaks of flour remain. The batter will be thick.
• Transfer the batter to the prepared 8"×8" pan and use a silicone spatula to spread and even it out.
• Bake for 15–17 minutes. The top should no longer look wet; a toothpick inserted into the center should come out with some moist crumbs but not raw batter. Remove from oven and place the pan on a wire rack to cool. The brownies will continue to set as they cool.
• (If you used the buckwheat flour alternative) Let the brownies rest in the pan about 2 hours before serving to allow them to finish setting.
• When the brownies have cooled enough to top (warm or room temperature), prepare the ganache: place the remaining 1 cup semi-sweet chocolate chips and 1/4 cup Irish cream in a small heatproof bowl.
• In a small saucepan over medium-low heat, warm the 1/4 cup whipping cream just until it is steamy and is about to simmer (do not boil). Remove the cream from the heat immediately.
• Pour the hot whipping cream over the chocolate chips and 1/4 cup Irish cream in the bowl. Let sit 30–60 seconds, then stir until the chocolate is completely melted and the ganache is smooth.
• Let the ganache cool for about 15 minutes, until slightly thickened but still pourable. Pour the ganache evenly over the cooled brownies and use a spatula to spread it to the edges.
• Allow the ganache to set at room temperature, or chill briefly to speed setting. Cover and store the brownies at room temperature for up to 2 days or refrigerate for up to 4 days. For fudgier brownies, refrigerate.