Recipe

Step 1:

Preheat the oven to 350F, and line a 6-inch cake pan (with a removable bottom) with parchment paper.

Step 2:

In a large microwave-safe bowl, heat cacao wafers, espresso powder, butter, and vegetable oil in the microwave for 30 seconds. Stir mixture thoroughly, then continue heating in 15 second intervals until chocolate has fully melted and the mixture is homogeneous. Set aside to cool slightly until warm but not hot.

Step 3:

In a small bowl, whisk together egg yolks, cacao powder, vanilla extract, kosher salt, and 1/4 cup sugar. Mixture will be thick.

Step 4:

Pour a few tablespoons of the chocolate sauce into the egg yolk mixture, and whisk to combine (this helps prevent the sauce from breaking or curdling). Transfer the chocolate-egg yolk mixture back into the chocolate sauce and whisk thoroughly.

Step 5:

Meanwhile, in a stand mixer fitted with the whisk attachment, beat egg whites on medium-high speed until just beginning to foam, about 30 seconds to 1 minute. Once foamy, and with the mixer on, slowly pour in the remaining 1/2 cup sugar. Continue whipping the egg whites to stiff peaks (be careful not to over whip).

Step 6:

Fold the egg whites into the chocolate mixture, then transfer the batter into the cake pan. Smooth the top with an offset spatula or the back of a spoon.

Step 7:

Bake in the oven for 30 to 35 minutes, or until a toothpick inserted into the center of the cake comes out clean (or mostly clean with a few dry crumbs). The top of the cake should have a thin crust with visible cracks.

Step 8

Remove from the oven, and cool the cake completely in the pan (if you try to remove the cake from the pan while it’s still hot, it will fall apart). Over time, the cake will begin to collapse.

Step 9

Use a knife to loosen the cake from the edges of the pan, then unmold the cake. Just before serving, whip the cream to soft peaks, then add the skyr and 2 tablespoons powdered sugar. Continue whipping the cream to firm peaks, incorporating additional sugar as needed. Layer the cream on top of the cake, then cut into slices and serve.