For the Crust

NutritionSortLoading...
Loading...

1 cup plus 2 tablespoons all-purpose flour

¾ cup sugar

¼ cup plus 2 tablespoons unsweetened cocoa powder

1 teaspoon kosher salt

9 tablespoons unsalted butter, chilled and cut into ½-inch cubes

Select allAdd

SortLoading...
Loading...

For the Dark Chocolate Ganache

2 cups heavy cream

1 ½ ounces fresh mint leaves, large stems removed (1 heaping packed cup)

1 ¼ teaspoons vanilla extract

¾ teaspoon kosher salt

14 ounces dark chocolate chips (60 to 70 percent cacao)

2 tablespoons unsalted butter, softened

Select allAdd

SortLoading...
Loading...

For the White Chocolate Layer

8 ounces white chocolate bars, broken up (see Tip)

3 tablespoons green crème de menthe

Select allAdd

1. Heat the oven to 325 degrees with a rack in the middle position. Line a 9-by-13-inch baking dish with two sheets of aluminum foil, allowing them to extend past the rim of the pan on all sides.

2. To make the crust, whisk together the flour, sugar, cocoa and salt in a large bowl. Add the cubed butter and mix with your hands, pinching the butter in, until it forms a crumbly, sandy texture.

3. Transfer the mixture to the lined pan and spread it out into an even layer that completely covers the bottom of the pan. Pack the mixture down firmly so it’s as smooth and flat as possible. Bake until dry-looking and set, about 25 minutes. Place the baking pan on a wire rack to cool for 10 minutes, then transfer to the fridge to chill.

4. Next, make the dark chocolate ganache: combine the cream, mint, vanilla and salt in a large saucepan. Heat the mixture over high until it comes to a strong, rolling boil. (Boiling is crucial in order for the ganache layers to set properly.) Turn off the heat, cover and let the mixture steep for 10 minutes.

5. After allowing to steep, place chocolate chips in a large mixing bowl and set a mesh strainer over top. Pour the cream and mint mixture through the strainer onto the chocolate to catch the mint leaves. Using a stiff spatula or the back of a large spoon, press as much liquid as possible out of the mint leaves and then discard the leaves. Let stand for 3 minutes, and then whisk until smooth. Add the butter and whisk until incorporated.

6. Pour half of the dark chocolate ganache (about 1 ¾ cups) onto the chilled crust, smoothing it out with an offset spatula into an even layer to the edges of the pan. Give the pan a few gentle taps on the counter to even out the ganache. Return to the fridge and chill for 45 minutes to an hour, until the dark chocolate layer is firmed up and set (it may not be rock-hard).

7. Melt the white chocolate in a medium heatproof bowl over a gently simmering double boiler (or in 10-second intervals in the microwave, stirring between intervals). Add the crème de menthe all at once and whisk vigorously until smooth and incorporated. (The mixture may separate a bit at first, which is OK.) Set aside to cool to room temperature, 5 to 10 minutes. (It should be cooled yet still pourable for the next step. Otherwise, it will begin to re-melt the dark chocolate layer.)

8. When the dark chocolate layer is firm and the white chocolate is cool, give the white chocolate mixture a vigorous stir and then drizzle evenly over the dark chocolate. Working quickly so it doesn’t set, smooth it out with an offset spatula into an even layer to completely cover the dark chocolate. Immediately give the remaining dark chocolate ganache a whisk to smooth it out again, then pour on top in an even layer, gently smoothing it out to completely cover the white chocolate. (If the white chocolate mixture or remaining dark chocolate ganache are no longer pourable, feel free to reheat briefly over the double boiler while whisking a bit.) Place back in the fridge to 'cure'.

Tip

For the best results, use a white chocolate in bar form, choosing one that has cocoa butter listed as one of the first ingredients — this will help ensure the white chocolate layer sets properly.