Step 1

Preheat the oven to 325 degrees. Butter sides and bottoms of a 9-inch springform pan.

Step 2

In a spice or nut grinder (or food processor or blender), pulse the almonds until finely ground. Then in a medium bowl, combine the flour, ground almonds, baking powder, baking soda, and salt together. Set aside.

Step 3

With an electric mixer or stand mixer, cream the butter and sugar until light and fluffy; about 5 minutes. Beat in the eggs, one at a time, until mixed, then add the almond and vanilla extracts along with the sour cream.

Step 4

Beat in the flour mixture just until mixed with no dry flour streaks.

Step 5

Transfer the dough to the springform pan. Smooth the batter with a spatula and sprinkle almonds and 2 tablespoons of granulated sugar over the top.

Step 6

Bake 40 minutes to 1 hour, or until the top is golden and springs back when lightly pressed. During the last 10 minutes of baking, place a sheet of parchment paper over the cake if it is browning too quickly. Cool in the pan on a wire rack before removing the sides of the pan. When ready to serve, sift powdered sugar on top and slice into wedges.