Instructions

for the filling

Combine apricots and water in medium saucepan and bring to boil over medium-high heat. Reduce heat to medium and simmer until fruit is softened and water is mostly absorbed, about 5 minutes. Stir in sugar and cook until liquid is thickened, about 3 minutes. Transfer mixture to food processor and process until smooth, about 30 seconds. Set aside and let cool completely.

for the dough

Combine flour, baking powder, salt, and lemon zest in bowl. Whisk sour cream, evaporated milk, and lemon juice in second bowl. Using stand mixer fitted with paddle, beat shortening, butter, and granulated sugar on medium-high speed until pale and fluffy, about 3 minutes. Add egg yolks and beat until combined. Reduce speed to low and add flour mixture in 4 additions, alternating with sour cream mixture in 3 additions, scraping down bowl as needed. Give batter final stir by hand. Divide dough into 3 equal pieces and form each piece into 5-inch square. Wrap squares in plastic and refrigerate until firm, 1 hour or up to 2 days.
Adjust oven rack to middle position and heat oven to 325 degrees. Line baking sheet with parchment paper. Working on floured counter, roll 1 dough square into 12 by 9-inch rectangle. Using fluted pastry wheel or pizza wheel, cut dough into twelve 3-inch squares. Place 1 heaping teaspoon filling onto center of each square and fold opposite corners over filling so they meet in center, enclosing filling completely.
Place cookies on prepared sheet and bake until golden brown, 20 to 24 minutes, rotating sheet halfway through baking. Let cookies cool on sheet for 5 minutes and then transfer to wire rack to cool completely, about 30 minutes. Repeat with remaining dough and filling. Sift confectioners’ sugar over cookies before serving. (Cookies can be stored at room temperature for up to 2 days.)