Preheat oven to 300 degrees.

Grease and flour a bundt pan

Cream butter and sugar with paddle

Add egg yolks (one at a time)

Add flour and soda slowly, alternating between that and sour cream.

Beat well - it is a THICK batter.

In another bowl, beat egg whites stiff with sugar.

Fold egg whites into batter

Pour 1/2 to 2/3 of batter in the pan.

Sprinkle half of the sugar mixture in the center.

Top with remaining batter.

Sprinkle with remaining sugar mixture on top.

Bake for 85-90 min.

Cake is done with a toothpick comes out clean. (Better underbaked than over!)

Let cake sit for 10 minutes

Flip over and cool on a cooling rack