Preheat oven to 350 degrees F. Lightly butter a 9" springform pan. Sprinkle with granulated sugar and shake to coat the bottom and sides, then tap out excess sugar.
In a medium microwave safe bowl, combine the chocolate, butter, and oil. Microwave for 45 seconds, check the chocolate and stir. Continue at 30 second intervals until the mixture is just about melted, then stir until smooth (this step can get out of hand fast, so be careful). Let chocolate cool to room temperature.
Separate 4 eggs, placing whites and yolks in separate medium bowls. Along with ¼ cup sugar, salt, cocoa and espresso powder, add remaining three (two at sea level) whole eggs and vanilla. Whisk until smooth; slowly blend yolk mix into chocolate mixture. Combine well.
With an electric mixer on high speed, beat the egg whites until foamy. While the mixer's running, slowly add the additional ½ cup sugar, beating until still peaks form. Try to avoid over-mixing or the peaks will be lost.
In two additions and until just incorporated, gently fold the egg whites into the chocolate mixture. At times this can seem counterproductive, but do your best to cover the whites with chocolate ; ) Spatula the batter into the prepared pan. Smooth the top with a spoon or offset spatula, then sprinkle the top with the remaining 2 tablespoons sugar.
Bake until the top puffs, starts to crack and the cake pulls from the side of the pan.High Altitude = 32 - 35 minutes.Sea Level = 35 - 45 minutes.Transfer the cake to a wire rack and cool completely in the pan. As it cools, the cake will "fall" and crack further.
Whipped Cream
About 15 minutes before ready to serve, chill a medium-sized (preferably glass or metal) bowl and the beaters from your electric mixer in the freezer.
Using an electric stand or handheld mixer—beat cream, mascarpone, confectioners' sugar and orange extract starting on medium-low until thick. Increase speed, add zest and continue until stiff peaks form. Avoid over beating.
Chocolate Curls
With a vegetable peeler or sharp knife, shave pieces or curls of chocolate from a baking or candy bar.
Before serving, add whipped cream; with an offset spatula or spoon, make fancy swirls, then add chocolate curls.Time to dazzle family and friends!
The changes at 6,300 altitude are an extra egg, half teaspoon vanilla, and baking fewer minutes than sea level.
Cake Notes
This cake can be made one day ahead, then covered in the pan and stored airtight at room temperature.
For a brownie like cake (dense) use coconut oil.
Whipped Cream Notes
For the best whipped cream, use a medium-sized deep glass or metal bowl.
place the bowl and beaters in the freezer for a minimum of fifteen minutes.
whipped cream can be made early, covered, and refrigerated for up to a few hours.
I include a zest range for those who like to love orange flavor. If you aren't much into orange, swap out any extract of choice. None at all tastes great too.