Kolaches

Makes about 5 dozen cookies.
Taste Tip: This dough must be prepared in advance. This cookie is based on the Eastern European sweet yeast bun of the same name (pronounced koh-LAH-cheez).
4 cups flour, plus extra for rolling dough
1 envelope (¼ ounce) active dry yeast
2 cups (4 sticks) cold butter, cut into small pieces
2 egg yolks
1 cup sour cream
3 egg whites
1 cup granulated sugar
About 2 cups apricot or raspberry preserves
Powdered sugar for garnish
Directions
To prepare pastry: In a large bowl, sift flour. Sprinkle yeast over flour. Using a pastry cutter or fork, cut butter into flour until mixture resembles coarse meal. Add egg yolks and sour cream and stir until well-combined (dough will be thick). Cover bowl with plastic wrap and refrigerate at least 4 hours, preferably overnight.
To prepare cookies: When ready to bake, preheat oven to 350 degrees and line baking sheets with parchment paper.
In a bowl of an electric mixer on medium-high speed, whip egg whites for 2 minutes. Slowly add granulated sugar, whipping egg whites to stiff, glossy (but not dry) peaks and reserve.
On a lightly floured work surface, using a lightly floured rolling pin, roll 1 cup of cookie dough (keeping remaining dough in refrigerator so it remains firm) to thickness of pie crust, roughly 1/8- to 1/4-inch thick.
Using a 3-inch cookie cutter or a pastry or pizza cutter, cut dough into 3-inch squares and place cookies 2 inches apart on prepared baking sheets. Repeat with remaining dough, gathering up scraps, re-rolling and cutting until all dough is used.
Fill each square with ¾ teaspoon fruit preserves and one generous teaspoon of meringue. Pull corners of cookie into center and pinch gathered corners together tightly. Bake cookies, 1 sheet at a time, until pastry is golden brown (cookies will reopen during baking), about 25 minutes. Remove from oven and cool 2 minutes before transferring cookies to a wire rack placed over wax paper to cool completely. To garnish, fill a wire sieve with powdered sugar and gently tap out powdered sugar over cooled cookies.
2009 Finalist: Pat Monson Johnson of Eden Prairie, Minnesota