Step 1

Preheat the oven to 375 degrees F. Place an 8-inch springform pan on a sheet of parchment paper and draw a circle around the circumference of the pan. Then cut the circle out. Place in the springform pan and butter the pan. Add 1 T flour and tap out any excess.

Step 2

Melt the chocolate and butter in a heatproof glass bowl, as well as the 8 T of sugar, if using unsweetened sugar as I did in a double boiler. Reserve the 1/3 cup of sugar until later. Set aside chocolate and butter mixture to cool slightly, about 5 minutes.

Step 3

In a separate small bowl, combine the 4 egg yolks, dissolved coffee and vanilla extract and whisk until just blended. Combine this yolk mixture with the chocolate mixture whisk until well blended.

Step 4

In a very clean, large glass bowl beat the 4 egg whites on medium-high and add the cream of tartar or lemon juice and beat until soft peaks form. This should take about 3 minutes. Beat another minute while slowly adding the 1/3 cup of granulated sugar. Then beat 1 more minute. The whites should be stiff. Using a rubber spatula, gently fold the egg whites into the chocolate mixture in 3 different batches until no white streaks remain.

Step 5

Pour the cake batter into the prepared springform pan and smooth the top. Bake in the oven on a center rack for about 20 minutes. The cake is done when a knife inserted comes out clean. Transfer to a wire rack and let cool for at least 1 hour. Run a knife along the edge of the pan to loosen the cake and then release the sides of the springform pan and lift off. Use a spatula to separate the cake from the bottom and lift off the parchment paper.

Step 6

In a clean glass bowl, whip the whipping cream until it starts to form peaks and add the chai and powdered sugar. Continue to whip until soft peaks form. Do not over whip or it will turn into butter.

Step 7

Serve with a dollop of chai-spiced whipped cream.