Chocolate Espresso Torte - cooking recipe

Ingredients

5 ounces semisweet chocolate, chopped
3 ounces unsweetened chocolate, chopped
1/4 lb unsalted butter (8 tablespoons, cut into pieces, plus more for the pan)
4 eggs, at room temperature
1/2 cup sugar
1/4 cup brewed espresso, cooled to room temperature
1 tablespoon sifted finely ground espresso beans
1/4 teaspoon salt
1/4 cup all-purpose flour, plus more for the pan

Preparation

Preheat oven to 350\u00b0F Butter an 8-inch cake pan (I used a springform pan) and line bottom with parchment paper. Butter the parchment and lightly flour (or use cocoa) the pan, shaking out excess.
In a small, heavy-based saucepan, melt chocolate and butter over medium heat, stirring frequently. Set aside.
Using the whisk attachment of a stand mixer, whip the eggs, sugar, brewed espresso, ground espresso beans, and salt on medium-high speed until thick and voluminous, at least 8 minutes (I mixed about 10 minutes). Turn the mixer to low and mix in the chocolate-butter mixture. Turn off mixer and sift the flour over the batter and fold until all the ingredients are fully incorporated.
Pour batter into prepared pan and bake until a skewer inserted in the center comes out clean, 25-30 minutes.
Cool in the pan on a rack for 10 minutes. Set a plate over the torte and carefully invert the torte onto the plate; peel off the parchment. Flip the torte back onto the rack to cool completely before slicing. (Since I used a springform pan, I let it cool completely in the pan.).