Prep Your Pans: Preheat your oven to 350°F / 175°C. Generously butter two 8-inch round cake pans.
Line the bottoms with parchment paper, then butter the paper as well. This ensures your delicate cakes will release perfectly.
Make the Torte Batter: In a blender or food processor, combine the eggs and sugar.
Blend on high until the mixture is pale, thick, and well combined.
Add the walnuts and blend again until they are very finely ground into the batter.
Finish the Batter: In a small bowl, whisk together the flour and baking powder.
Add this dry mixture to the blender and pulse just until a smooth batter forms. Be careful not to overmix.
Bake the Torte Layers: Divide the batter evenly between your prepared pans.
Bake for 17 to 19 minutes, or until the tops are golden brown and spring back when lightly touched.
Let the cakes cool in their pans on a wire rack for 5 minutes.
Cool the Cakes: After 5 minutes, carefully invert the cakes onto the wire rack.
Peel away the parchment paper and let them cool completely, which will take about 1 hour.
Start the Ganache: While the cakes cool, make the icing.
In a medium saucepan, combine the heavy cream, chopped chocolate, sugar, and instant coffee.
Place over medium heat.
Heat and Melt: Whisking constantly, bring the mixture just to a boil. As soon as it begins to bubble at the edges, remove it from the heat.
Continue to whisk until the chocolate is completely melted and the ganache is smooth and glossy.
Chill the Ganache: Pour the ganache into a large metal or glass bowl.
Place it in the refrigerator to chill until it's completely cold. This can take a few hours, or you can chill it for up to 24 hours.
Stir it occasionally as it cools to ensure it chills evenly.
Whip to Perfection: Once the ganache is thoroughly chilled, use an electric mixer (with chilled beaters, if possible!) to whip it on high speed until it becomes light, fluffy, and holds stiff peaks.
Assemble the Torte: Place four strips of wax paper around the edge of your serving platter to keep it clean.
Place one cake layer, top-side down, in the center.
Spread about one-third of the whipped ganache over this layer.
Add the Final Layer: Gently place the second cake layer on top, bottom-side up, to create a perfectly flat surface. Use the remaining ganache to frost the top and sides of the torte, smoothing it with an offset spatula.
Garnish and Chill: Decorate the top with chocolate curls. Carefully pull out the wax paper strips from under the cake. To protect the frosting, you can insert a few toothpicks around the top edge before covering loosely with plastic wrap.
Chill until you're ready to serve.
