This cake is a winner! Every time I make people ask for the recipe. I can't remember where I got the original recipe but I know I tweaked it here and there. It's VERY important that all your ingredients are at room temperature before you start. If they aren't, the butter and almond paste will seize up and the texture will be off. This cake is surprisingly full of flavor and moist.
2 sticks butter, softened, room temperature
1 cup sour cream, room temperature
1 tsp baking soda
2 cups sifted flour (measured after sifting)
½ tsp salt
1 ½ cups sugar
7 oz almond paste, cut in small pieces
4 egg yolks, room temperature
1 tsp almond extract
Preheat the oven to 350 degrees F. Butter the sides and bottoms of one 9-inch spring form pan; line sides and bottoms with parchment paper then butter the paper.
Mix together the sour cream and baking soda in a small bowl. Sift the flour and salt into another bowl.
In the bowl of an electric mixer fitted with a paddle, cream the butter and sugar until fluffy. Then add the almond paste, a little at a time, at medium speed, it should take about 3 - 4 minutes to add the paste. You want to do this slowly so that it all gets incorporated and the batter doesn't end up having little balls of almond paste in it. Then leave the mixer on and let it all beat together for 8 minutes.
Beat in the egg yolks one at a time, and mix until incorporated. It will look curdled; don't worry.
Blend in the almond extract and sour cream mixture. Reduce mixer speed to low and gradually add the flour mixture, just until blended.
Pour the batter into the prepared pan and spread evenly. Bake about 1 hour. It is done when you press the top and it returns to its shape, and also shrinks from the sides of the pan. Remove from the oven and place on a baking rack to cool in the pan. The middle will fall down, don't worry that is normal.
When you are ready to serve the cake, sift confectioners' sugar on top. You can also decorate it a bit with slices of toasted almonds.