- 1/3 cup unsalted butter
- 6 ounces semisweet chocolate
- 2 teaspoons espresso coffee grounds
- 2 large eggs
- 3/4 cup granulated sugar
- 1/4 teaspoon salt
- 1/2 cup all-purpose flour
- 2 ounces pure white chocolate
- 1 tablespoon 35% whipping cream
- 1/2 teaspoon espresso powder
- 1 teaspoon flaked sea salt, for sprinkling
Preheat your oven to 350°F. Line an 8x8-inch metal baking pan with parchment paper leaving a 2-inch overhang at each side.
Melt together butter and chocolate either in a saucepan over very low heat or in the microwave with frequent stirring until smooth.
In a large bowl, combine eggs, sugar, salt and espresso powder and whisk vigorously for 20 seconds until well blended and smooth. Whisk in warm melted chocolate mixture. Sprinkle in the flour and stir it through.
To make the mocha swirl, combine white chocolate, cream and espresso powder in a bowl and microwave until melted. Stir until smooth.
Pour the batter into your prepared pan and spread it out evenly. Dollop white chocolate mixture over batter and swirl through the batter. Bake for 20-25 minutes, or until slightly puffed and a skewer inserted into the center comes out with a few moist crumbs. Transfer pan to a wire rack and let cool completely in the pan.