Preheat your oven to 350°F and place the baking rack in the middle position. Grease a 9-inch springform pan using 1 tablespoon of softened butter. Sprinkle 1 tablespoon of powdered sugar around the pan, tapping out the excess, then set it aside.

In a medium bowl, combine the flour, baking powder, and salt, whisking them together. Set aside.

In a large bowl, use a hand or stand mixer with a paddle attachment to cream the softened butter, sugar, and ricotta cheese until the mixture is light and fluffy, about 5 minutes. Beat in the eggs and almond flavoring for an additional minute. Gradually add the flour mixture, mixing until just combined. Gently fold in the finely chopped almonds.

Transfer the batter into the prepared springform pan. Bake in the center of the oven for 45-55 minutes, or until a toothpick inserted into the center of the cake comes out clean. Allow the cake to cool in the pan for at least 10 minutes before releasing it from the springform and transferring it to a wire rack to cool completely.

For the finishing touch, sprinkle the sliced almonds over the cooled cake. Use a fine mesh sieve to dust the top with powdered sugar until lightly covered.