Preheat oven to 180°C (350°F).
Prepare an 8-inch cake pan by greasing it with butter and lining it with a parchment paper.
Use a food processor (or a blender) to grind the almonds until you get a coarse texture.
Using a large bowl, combine the softened, unsalted butter with half of the sugar. Use a hand mixer to beat the mixture until it gets creamy.
Add the egg yolks one at a time.
Add Amaretto and continue mixing.
Add cooled, melted chocolate, and mix.
Add ground almonds and mix. You can also use a rubber spatula or wooden spoon to mix the chocolate mixture at this point.
Using a medium-sized bowl, combine the egg whites and a pinch of salt.
Clean the mixer's beaters and, using a low speed, beat the egg whites into soft peaks.
Switch the mixer into high-speed and slowly add the remaining sugar while beating the egg whites continuously – until you see stiff peaks.
Add a third of the beaten egg whites into the chocolate mixture and fold to combine. (Note: It would help if you used a rubber spatula or wooden spoon to do this.) Continue adding and folding until you've used all the beaten egg whites. Do not overmix, just enough to combine.
Pour your torta caprese batter into the prepared pan. Use a spatula to level the top of the cake.
Place your cake pan in the lower part of your oven for 55 to 60 minutes.
Remove the pan from the oven and set aside to cool down.
Dust your caprese cake with powdered sugar and serve.