Mouthwatering Flaky Turnovers

Heat dates, water, and 1/4 cup brown sugar in a saucepan over medium heat; cook, stirring occasionally, until dates are very soft, about 5 minutes. Set aside to cool to room temperature.

Stir together milk and vinegar in a small bowl; set aside to curdle, about 10 minutes.

Whisk together flour and baking soda in a large bowl; stir in oats and remaining 1 1/2 cups brown sugar. Stir in melted butter, melted shortening, and curdled milk mixture until well combined; cover dough and refrigerate until firm, about 1 hour.

Preheat the oven to 350 degrees F (175 degrees C). Line baking sheets with parchment paper.

Roll dough out on a lightly floured surface, about 1/8-inch thick. Cut out dough circles with a round cookie cutter. Place about 1 tablespoon date mixture in the center of each circle; fold in half and press edges together tightly to seal. Place cookies on the prepared baking sheets.

Bake in the preheated oven until golden, about 10 minutes. Remove to cool completely on a wire rack.