01 -
Butter and line an 8x4-inch loaf pan with parchment paper, allowing excess to hang over edges for easy removal.
02 -
Microwave chocolate chips and unsalted butter together in 30-second increments, stirring until smooth and glossy.
03 -
Stir in Dutch cocoa powder, granulated sugar, and instant espresso powder into melted chocolate until sugar begins to dissolve.
04 -
Whisk in one large egg and one egg yolk vigorously for one to two minutes until mixture is smooth and fudgy.
05 -
Sprinkle all-purpose flour and sea salt over batter, folding gently just until combined without overmixing.
06 -
Spread batter evenly in prepared pan and bake at 350°F (175°C) for 25 to 30 minutes until edges set and center wiggles slightly; internal temperature should reach 180°F (82°C) if checked.
07 -
Prepare a strong shot of espresso or concentrated cold brew and let it cool completely; mix with coffee liqueur if using.
08 -
Quickly dip each ladyfinger in cooled espresso mixture and arrange in a single layer over the cooled brownie base.
09 -
Whip the mascarpone cheese, vanilla bean paste, and granulated sugar gently until combined; gradually add chilled heavy cream and whip on medium speed until soft peaks form, then refrigerate until ready to use.
10 -
Spread or pipe mascarpone cream evenly over the soaked ladyfingers layer for a smooth, fluffy finish.
11 -
Refrigerate assembled layers for at least one hour to set; before serving, dust the top generously with Dutch process cocoa powder and slice with a sharp knife.