Grease a 10 cup bundt cake pan with shortening, then dust it with flour.
Using a mixer, cream together the butter and sugar.
Add the egg yolks (reserve the egg whites) one at a time, beating between each addition.
Add the vanilla and almond extracts. Beat again.
Add the baking soda, salt and half of the flour.
Add in half of the sour cream, mixing well.
Add in the remaining flour, mixing well, then mix in the rest of the sour cream. Beat until well combined.
In a clean bowl, beat the egg whites until they are stiff and can hold peaks.
Gently fold the egg whites into the cake batter, folding until completely combined.
Pour the batter into the prepared pan and bake for 60-70 minutes or until the cake bounces back when you touch it. The exact time will depend on the size and shape of your pan so watch it closely.
Allow the cake to cool for 10 minutes, then turn it out onto a cake plate to cool completely.
Once the cake is completely cool, dust with powdered sugar.
Store the cake in an airtight container at room temperature.
The calories shown are based on the cake being cut into 12 pieces, with 1 serving being 1 slice of cake. Since different brands of ingredients have different nutritional information, the calories shown are just an estimate.