2 sticks unsalted butter, softened
1 cup sour cream
1 tsp baking soda
2 cups all purpose flour
½ tsp salt
1 ½ cups sugar
7 oz tube or 8 oz can almond paste
4 egg yolks
1 tsp almond extract
1. Preheat oven to 350°F. Butter the sides and bottom of a springform pan and, optionally, line the bottom with parchment paper. Butter the paper.
2. Mix sour cream and baking soda in a small bowl. Sift flour and salt together into another bowl.
3. In the bowl of an electric mixer, or in a food processor, or in a bowl with a hand-held electric mixer, cream together the butter and the sugar. Add the almond paste, a little at a time, and beat for 8 minutes.
4. Beat in the egg yolks one at a time. Blend in the almond extract and sour cream mixture.
5. With the beaters on low speed, gradually add the flour mixture, and mix just until blended.
6. Pour batter into prepared pan and smooth out the top.
7. Bake about 1 hour. The cake is done when you press the top and it returns to its shape, and the cake pulls away slightly from the side of the pan. Cool for 10 minutes before removing from the pan.