Into a stand mixer (or a mixing bowl) add 2 egg yolks, 2 cups of sour cream and 2 cups of sugar. Stir to combine and then add 4 cups of flour and stir some more on low speed just until the dough comes together. If the dough seems too sticky, add 1/2 cup more flour and mix well until the flour is all incorporated.

Transfer the dough to a lightly floured surface and roll out to a thickness of about 1cm. (lightly dust your rolling pin with flour also to avoid sticking.

Using a round cookie cutter or a cutter of your choice, cut out the cookies, place on a baking sheet lined with parchment paper dipping the cutter into flour after each time to avoid sticking. You can also use a glass if you don't own any cookie cutters.

Once you've pressed all the cookies, preheat the oven to 350°F and bake the cookies for 8-10 minutes or until the bottom of the cookies are lightly browned.

Combine egg whites with powdered sugar and beat until it is a thicker yet smooth running consistency. If you whip it for too long the glaze will become thick and leave bumps on the finished cookies. If you overwork the glaze, add a teaspoon of milk or water at a time and mix it in until you get the desired consistency.

Once the cookies are baked, carefully dip each cookie top into the icing sugar glaze while the cookie is still hot. (careful not to burn your fingers) and place them back in the oven for additional 2-3 minutes for the glaze to dry up and not be sticky. Allow to cool on a cooling rack and enjoy.