Directions

1. In a medium bowl, whisk together the flour, baking soda, baking powder, salt, and lemon zest; set aside. Line a baking sheet with parchment paper, and set aside.
2. In the bowl of an electric mixer fitted with the paddle attachment, combine butter and 1 cup sugar; beat until light and fluffy, about 5 minutes. Add egg, and beat until just combined. Add cream cheese, buttermilk, and vanilla extract; beat until well combined. Add the reserved flour mixture, and beat until smooth. Form the dough into a ball, and cover with plastic wrap; flatten into a disk, and refrigerate at least 1 hour.
3. Remove dough from refrigerator. Sprinkle a clean work surface with flour; roll dough 1/8 inch thick. Using a 4 1/2-inch-round cookie cutter, cut out 20 rounds, and transfer to prepared baking sheet. Cover with plastic wrap, and refrigerate until firm, about 30 minutes.
4. Combine sun-dried strawberries and 1 1/2 cups water in a medium saucepan. Scrape in the vanilla seeds, and reserve pod for another use. Bring mixture to a boil. Reduce heat to low, and simmer until most of the water has been absorbed, about 20 minutes. Remove from heat, and stir in lemon juice, lemon zest, and preserves. Set aside to cool.
5. Heat oven to 375 degrees. have ready a small bowl of ice water. Remove chilled dough from the refrigerator, and let stand until pliable, 2 to 3 minutes. Spoon 1 tablespoon of filling onto the center of a round, and brush ice water around the edges. Fold round in half; using a fork, press down on edges to seal. Repeat with the remaining rounds. Chill 30 minutes.
6. Remove pies from refrigerator, and brush tops with egg white. Sprinkle remaining 1/4 cup sugar over tops. Bake until golden brown, about 20 minutes. Remove from oven; transfer to a wire rack to cool. Serve.